Add a Tachometer

[Quimrider]

https://i.postimg.cc/bZLsdsZV/tachgroup2.jpg (https://postimg.cc/bZLsdsZV)
http://powersportsoutletstore.com/product/33-3910

[strike:3eovo2fv]About 57 dollars after shipping. [/strike:3eovo2fv] This is not a fancy tach. just a plain and simple 8K RPM tach.

Update 08/17/10: Powersportsoutletstore.com has entered the dustbin of history.

I found what appears to be the same tach at BKrider for $39.99 + $8 and change shipping. (http://www.bkrider.com/bkrider/skusearch_v3.asp?scriteria=C01160541)


Additional parts needed for install
- Zip ties as needed.

Tools required:
- Soldering iron and solder.
- Socket set preferribly with extensions.

Overview:
This is a quick installation guide for the above tachometer. Installation should take about 1/2 hour. All wiring is done directly to the ignition coil for the simplest wiring. If you want to get creative there are other way you can do it. There are two wires that attache to the ignition coil with female blade connectors. The one on the right side of the bike is the negative and the one on the left is the + 12V. We will be soldering to these female blade connectors and using the mounting bolt of the ignition coil as a grounding point.

Step 1 Mounting:
https://i.postimg.cc/zbyLs8Xt/T1.jpg (https://postimg.cc/zbyLs8Xt)https://i.postimg.cc/HcFJHRrp/T2.jpg (https://postimg.cc/HcFJHRrp)
- Use the conviently located bolt shown in the picture for attaching the tach with the included bracket.
- Remove the nut and washer
- Slide tach over bolt
- Put washer and nut back on.
- If you don't like that the tach is at an angle you could easily make a custom bracket so it is at the same angle as the spedometer.

Step 2 Wiring:
https://i.postimg.cc/k2yt8Tpc/T3.jpg (https://postimg.cc/k2yt8Tpc)https://i.postimg.cc/gwSXtndL/T4.jpg (https://postimg.cc/gwSXtndL)
- This wiring diagram was the only instructions that came with the tach.
- These are the wires we have to work with.
looking at the diagram we will be connecting the green wire to the negative terminal on the coil. Since our lights come on when the key is switched to "on" we might as well have the light for the tach and the power for the tach switch on with the key as well. It just convienently happens that the +12V for the coil is also switched on when the key is in the "on" position. So we will connect the red and blue wire to the +12V terminal on the coil. The last remaining wire is the black ground wire. Also convienently there is a mounting bolt inbetween the coil terminals. We will connect the black wire to this bolt for a ground.
- Remove the gas tank (see service manual)
- Route wire from tach to the front of the ignition coil.
- Leaving a couple extra inches cut the excess lenght of wire off.
- Trim back the black outer shell a couple inches to expose individuals colored wires inside. BE CAREFUL NOT to accidentally cut the individual wires when trimming back the outer shell!

https://i.postimg.cc/gLRx0sh3/T5.jpg (https://postimg.cc/gLRx0sh3)
- Disconnect the two wires with the female blade connectors from the coil and slide back rubber insulators. It may be easier to slide back the rubber insulators first to disconnect the female blade connectors.
- The wire that was connected to the left side coil terminal is red, This is the +12V. The white wire connected to the right side coil terminal is white and the negative wire.

(Note: this is on my 2000 GZ250. Other years may have different wire colors. To be sure, use a multimeter to see which one of these supplies +12V with the key switched to "on".)

EDIT NOTE: As suggested by another member I have switched to pulling the +12V from the horn. Switch the key to the on position and use a multimeter to see which of the two horn wires has +12V with a multimeter. Either way will work, but pulling +12V from the horn circuit is probably a better idea. Using the horn circuit may help with idle and idling if you have a low battery. Also my needle "bounced" less at 1000 to 1500 RPM after moving the power source to the horn circuit.

- Slide the red and blue wires from the tach up thru the rubber insulator on the red coil wire.
- Solder these wires to the back part of the female blade connector.
- Repeat the above 2 steps soldering the green wire from the tach to the white wire with the female blade connector.
When done soldering it should look like this:
https://i.postimg.cc/18SqfkJX/T6.jpg (https://postimg.cc/18SqfkJX)
- Connect the remaining black wire to the coil's mounting bolt inbetween the terminals for the ground wire.
- Slide the rubber insulators back over the female blade connectors.
- Reconnect the blade connectors to their respective terminals on the coil.
- Finally secure the wire in place with zip ties.
This is what it should like.
https://i.postimg.cc/rdFR9S6L/T7.jpg (https://postimg.cc/rdFR9S6L)
Put your gas tank back on and go for a ride :cool:
Remember to be safe and keep your eyes on the road. Don't get too distracted by your new tach.

[jonathan180iq]

Awesome Stuff. Good work. It looks pretty solid.
When you get a chance, can you throw us a few tach/speed readings?

What's the RPM in 5th at 60mph and so on?

Take care,
Jonathan

[Quimrider]

I'll have to check when I can find some wide open traffic free road. I can tell you that at 75mph it's a tick over 7500 rpm. Probably between 7550 and 7600 RPM. I still have the stock 15t front sprocket. I've been trying to get a 16t front sprocket from bike bandit since June. They can't seem to get any. It idles at about 1000 RPM. The tach is real bouncy at 1000 RPM but completely smooths out by 2000 RPM. Who knows if the gauge is accurate but the numbers seem to be reasonable.

[Quimrider]

I went for a ride at lunch and watched my RPM's at 30, 40, 50, and 60 MPH in 5th gear. It looks like I could use my tach as a spedometer! The only one I know for sure is that at 40MPH it was exactly 4000 RPM I had to watch the road and couldn't tell exactly but it looks like 3K RPM = 30MPH, 4K = 40, 5K = 50, 6K = 60 MPH. It doesn't help that my tach is mounted at a slight angle so getting a precise reading is difficult.

[shmeel]

Will the tach spin in the mount? Does it have a bolt on the bottom to loosen it from the mount or is the housing and mount one piece?

Thanks

[Quimrider]

nope. if you look at this picture, it shows the back. there are 2 studs coming out of the tach that go thru two holes on the mounting bracket. Since the mounting bracket is just a flat piece of metal with holes you could easily make your own bracket and put it at any angle you want.
https://i.postimg.cc/bZLsdsZV/tachgroup2.jpg (https://postimg.cc/bZLsdsZV)

[trykemike]

quimrider is there any issue when adding the tach re: power draw against the coil ?

will this addition affect reliability ?

[Quimrider]

I don't know how much current the tach draws, but I can't imagine it would be very much at all. The light bulb in the tach probably draws more current than the tach itself. If it were to draw too much current, you'd blow a fuse before you would see ignition problems. Well... you'd see ignition problems when you blew a fuse! :lol: I've gone thru several tanks of gas with no problems. If you're still concerned about current draw you could simply not hook up the blue wire (light bulb) or you could wire the power for the tach and light bulb in with the headlight circuit. Although I think this would be a waste of time.

In my VW Beetle the tach, ignition coil, fuel shutoff solenoid, and the electric choke are all powered from the same circuit. I haven't looked at the schematic for the GZ250 electrical system but I'd imagine there is more on the ignition coil circuit than just the coil.

[Easy Rider]

If it were to draw too much current, you'd blow a fuse before you would see ignition problems.

Then again maybe not. Remember that this bike will stop firing with a weak battery BEFORE it gets too weak to turn the engine over. :roll:


you could wire the power for the tach and light bulb in with the headlight circuit. Although I think this would be a waste of time.


Well again, maybe not. Having the tach powered off of the positive side of the coil might explain why the reading is "jumpy" at low revs. :cry:

[Quimrider]

Then again maybe not. Remember that this bike will stop firing with a weak battery BEFORE it gets too weak to turn the engine over. :roll:
Interesting, I've never heard that. A good thing to know when I have a weak battery and it won't start.


Well again, maybe not. Having the tach powered off of the positive side of the coil might explain why the reading is "jumpy" at low revs. :cry:
I'll test this theory by temporarily running a fused wire from the battery for tach power.

[Easy Rider]

Remember that this bike will stop firing with a weak battery BEFORE it gets too weak to turn the engine over. :roll:
Interesting, I've never heard that. A good thing to know when I have a weak battery and it won't start.


I found out the hard way.......twice before I got a new battery! :cry:

It has since been confirmed by others.

Them little suckers are expensive.......~ $85. :tdown:

[Dupo]

Quim, very good write up. Looks great and very easy to understand.

Good Job!

[Badbob]

[quote="Easy Rider":19od4bto]
Remember that this bike will stop firing with a weak battery BEFORE it gets too weak to turn the engine over. :roll:
Interesting, I've never heard that. A good thing to know when I have a weak battery and it won't start.


I found out the hard way.......twice before I got a new battery! :cry:

It has since been confirmed by others.

Them little suckers are expensive.......~ $85. :tdown:[/quote:19od4bto]

Jumper cables. I got mine. Used them once already. :)

Tiny little things.

[trykemike]

hey quimrider thanks again for the howto. I installed the tach last night. I made a modification to the original instructions.

1 - I took + 12 v from the orange horn wire after checking it with a volt meter it gave + 12 v when the key is switched on

2 - the connectors for the coil were encased in hard plastic which I did not want to break and the leads were very short so I threaded the wires through the ends of the connectors and folded them over then inserted the connector back onto the blade on the coil.

3 - I turned on the key the tach flexed the tach light came on I started the bike it reved to 4000 then quit after 30 secs. It would not start after several attempts.

4 - I took off the tank again and noticed a small black hose behind the main fuel line. I connected it to the nipple on the carb.
( vacuum line )

5 - after remounting the tank the bike fired up then I took it for a spin.

6 - the tach is smooth even at 1000 rpm

[Easy Rider]

1 - I took + 12 v from the orange horn wire after checking it with a volt meter it gave + 12 v when the key is switched on

6 - the tach is smooth even at 1000 rpm

Good job! :tup:

I wonder what the tach needle will do when you activate the horn ??? :roll:

[trykemike]

hey easyrider I tested the horn wire with a voltmeter and pressed the horn button no needle deflection was evident. I have tested the tach with the horn no problem.

[Easy Rider]

hey easyrider I tested the horn wire with a voltmeter and pressed the horn button no needle deflection was evident. I have tested the tach with the horn no problem.

Check. I wouldn't expect to see a deflection when set to measure DC. Just for curiosity, try setting your meter for AC and hit the button once. Them cheap horns tend to make "waves" on the feed line.
Anyhow, good that it works without interference.

[trykemike]

Hey quimrider since adding the tach I have on several occasions been able to pull 7500-7600 rpm with indicated speed of 125 kph. I usually run out of road space to get past this speed. Have you ever reached 8000 rpm in 5 th gear ?

[Quimrider]

before switching to the 16t front sprocket I could hit 80mph which = 8000RPM going down hill or with a decent tail wind. I've never been able to get past this. If you browse over to the 16t sprocket thread, I don't remember who but someone put up a nice graph of rpm vs speed with both the 15 and 16t sprocket. Since adding the 16t sprocket, the fasted I could go was 79mph. I don't remember what RPM's that was but the graph should give you an idea. If you're considering the 16t front sprocket. It makes riding in town better since it spreads the gears out a bit and on the highway the engine doesn't sound so angry. The only down side is that is may have knocked a couple mph off my top speed as it takes longer to get up to 75mph and very difficult if not impossible to go faster. Although 4th is usable up to about 65 for going up hill. and if you don't like it, you're only out about 18 bucks and another 20 minutes to switch back to the old sprocket.

[zepfan1232]

What RPM does the engine redline at?

[Quimrider]

Good question. I've never been able to find a definitive answer. I would guess 8000 or maybe 8500. My tach only goes up to 8000 but I have inadvertently over revved a couple of times to 9500-10000 estimated. and thankfully my engine is still in one piece.

[bigwonton]

Great writeup! I just installed the same tachometer this weekend and it's great being able to actually see what RPM the engine is running at. Everything went smoothly. My biggest fear was that the tank would be a pain to take off but it came off quite easily. I think I spent the most time trying to contort my fingers so I could get the nut back on the bolt after putting on the tach.

If I get adventurous, I might try bending the mounting bracket a little bit so that the tach angles in towards the rider like the speedo.

[jonathan180iq]

I'm installing mine tomorrow. How about some more photos from everyone?

The one that I purchased is a smaller model than the one lister here. I got from Dennis Kirk for $70.
We'll see if the install in the same. It should be pretty straight forward.

By the way, the service manual says the redline is 8,000 rpm.

[bigwonton]

I'm installing mine tomorrow. How about some more photos from everyone?

The one that I purchased is a smaller model than the one lister here. I got from Dennis Kirk for $70.
We'll see if the install in the same. It should be pretty straight forward.

By the way, the service manual says the redline is 8,000 rpm.

No pictures, but a few suggestions. I would have some shrink tubing and some crimp lugs available to do the install.

For the ground wire, I used a round lug and attached it to the bolt on the center of the coil.

For the negative coil attachment, my blade connector had shrink wrap insulation which I had to cut off in order to solder the green wire. I then used new shrink-tubing to insulate it again.

I tied the power and illumination wires together and ran it back to the battery where I found a line that had switched +12v.

[jonathan180iq]

Finshed around11:30 pm.
It was only a 30 minute job but I also took time to teach a buddy of mine how to ride today.

I couldn't embed the video so here is the link:

http://www.youtube.com/watch?v=sG6C8hgr_cE

Only revved to 5k in the video since it was so late.
I'm glad I got this little thing.

[bigwonton]

Finshed around11:30 pm.
It was only a 30 minute job but I also took time to teach a buddy of mine how to ride today.

I couldn't embed the video so here is the link:

http://www.youtube.com/watch?v=sG6C8hgr_cE

Only revved to 5k in the video since it was so late.
I'm glad I got this little thing.

Looks nice! Where did you end up tapping the power/illumination from?

[jonathan180iq]

I ran a line back to the rear running light. It's wired under the tank.

This is probably not an ideal place for everyone. But, I didn't feel like uninstalling my fairing wiring the light up and then reinstalling everything.


http://www.postimage.org/aVEwiTA.jpg (http://www.postimage.org/image.php?v=aVEwiTA)
This is a 1 7/8" tach from Drag Specialties. (maybe specialists)
It's very nice. The chrome and black face match the OEM suzuki speedometer very nicely. The needle spools up with no deflection and it's operation is very smooth.

It's pulling juice from the horn wire, as suggested by others but I went with a simple ground to the frame. I installed wire-ends to the ground wire and bolted and mounted it onto and extisting bolt.

For the coil connection, I didn't have enough space so I cut the white Suzuki wire and extended it just a bit and mounted both the Suzuki white wire and the tach's coil wire to a new female blade connecter and slid the new assembly on the negative coil blade.

As with all of my wiring, it's a little ugly at the moment. When I have more time and I'm not distracted, I'll go back and clean them up and put weather-proof slides over the connections.

[bigwonton]

I'll post my installed pics as well:


http://www.postimage.org/gxKyoa9.jpg (http://www.postimage.org/image.php?v=gxKyoa9)


http://www.postimage.org/PqieX90.jpg (http://www.postimage.org/image.php?v=PqieX90)

[trykemike]

Hey guys now that you have the tach what cruising rpm sounds comfortable to you ?

I like 5000-5500 rpm. I have ran 20 km @ 6250-6500 without problems.

My top speed occurrs @ 8000rpm in 5th ( 80 mph ) 125-130 k/ph

Most days I can reach 7500 rpm in 5th 120 k/hr ( 75 mph ) max.

On longer rides 20 km + I just keep below 6000 rpm and the engine runs fine.

[jonathan180iq]

I shift between 5.5 and 6k.

In 5th, I cruise around 4800-5500.
Twisting through backroads, I stayed in 4th around 6k rpm for a couple of miles.

[Water Warrior 2]

Hey guys now that you have the tach what cruising rpm sounds comfortable to you ?

I like 5000-5500 rpm. I have ran 20 km @ 6250-6500 without problems.

My top speed occurrs @ 8000rpm in 5th ( 80 mph ) 125-130 k/ph

Most days I can reach 7500 rpm in 5th 120 k/hr ( 75 mph ) max.

On longer rides 20 km + I just keep below 6000 rpm and the engine runs fine.

Interesting info. With all that has been said and done I would think the 250's have a sweet spot at about 6000 rpm in most cases. Thanks.

[jonathan180iq]

I get the most pull between 5500 - 6500, for what it's worth.

Anyone ever dyno-ed one of these things?

[Sarris]

Installed my tach today. I used the one from the Power Outlet Store listed in the first thread. It arrived in just 2 days. (WOW) I installed it in about 30 minutes. I used the horn hot wire for both the 12v+ connection and for the light connection.

It all seems to works as it should. Mine has just a little "bounce" at idle and I wondered if everyone elses does that as well.

:??:

Kudos to the Quimrider for his excellent How To.

[jonathan180iq]

Does it look like an electrical bounce or the bounce that you would expect to get from differing idle readings?

I have no bounce. I get a little wobble, with idle, when sitting at a redlight for a long time.

PS:
I also had to cut and rewire my coil wire to get a little extra slack. In doing so, I upgraded to a slightly thicker wire. This may have something to do with it.

[Sarris]

It's just a little wobble. More like a slightly unsteady idle. I've double checked all my connections and all is OK. The more I think about it, I'm fairly sure its a combination of an unsteady idle and a cheap tach. I compared it to the one in my Scion XB and it does the same thing, so I'm pretty sure it's OK.

I'll keep an eye on it. Thanks for the response.

:2tup:

[Quimrider]

yea a little bounce is near idle is what you get with this tach. Mine did this less when I switched from using the coil +12V to the horn +12V.

[5th_bike]

Installed mine today, it is the one from Dennis Kirk (1-7/8") part # 40-7646 for $69.95 plus $6.95 shipping.

I mounted it at the bolt that holds the right turn signal assembly. The tachometer dial is almost straight with only a degree or two rotation, hardly noticeable.

The zip tie that holds wires and front break hose together, needed loosening in order to mount it. No need to cut it, just lift the little lip that sticks out of the 'cube' and it will loosen. It can be tightened in place again after mounting.
Also I needed to temporarily undo the break hose from its holder at the left fork, about halfway down, to loosen it and to make space for mounting the tach. Now the brake hose sits snug around the tach.

See pictures below. Sorry for the crummy picture quality, it was getting dark and I didn't use the flash.

Thank you QuimRider for the inspiration :2tup:

Thank you TrykeMike for suggesting to power it from the horn +12V, it works like a charm and the only wobble at low revs is due to actual rev fluctuations. :rawk:

And thank you JonathanIQ180 for finding that nice little tach at Dennis Kirk. :tup:

http://www.postimage.org/Pq1I8UHi.jpg (http://www.postimage.org/image.php?v=Pq1I8UHi)

http://www.postimage.org/aV1wtcei.jpg (http://www.postimage.org/image.php?v=aV1wtcei)
http://www.postimage.org/aV1wuj4i.jpg (http://www.postimage.org/image.php?v=aV1wuj4i)

[5th_bike]

OK I wanted to post some better pictures, here they are:

Right after starting it, with the choke on:

http://www.postimage.org/gx2RYOH0.jpg (http://www.postimage.org/image.php?v=gx2RYOH0)


Overview, how it looks like on the bike:

http://www.postimage.org/gx2RYRb9.jpg (http://www.postimage.org/image.php?v=gx2RYRb9)


Close-up from front (and, sorry for not cleaning the dried bug guts from the signal light stem, and for having the brake hose, gas cables and the wires obstruct the view):

http://www.postimage.org/gx2RZ7E9.jpg (http://www.postimage.org/image.php?v=gx2RZ7E9)


And then, here is my very first cinematographic accomplishment on youtube, showing the tach in operation:

http://www.youtube.com/watch?v=tEiJ-RFkKiU

I'm glad it works but it IS an extra distraction....

[ppronti]

Hey Guys (and Gals):

I know none of you has ever heard from me before, but I have spent about 10 hours (probably even more) studying the electrical schematics of this bike from the Service Manual. Anyway, if you would allow me to offer my “two cent’s” worth as far as this tachometer modification goes, my suggestion represents how a tachometer would be OEM “Engineered” into the bike. Please do note that the following suggested wiring is accompanied with explanations that any of you can verify on any version/revision of the schematics of this bike, and (therefore) is a [*nearly*] universal fit. [This statement is qualified because, according to the service manual revision I have (which covers through model year ’07), there is a significantly different schematic for “Country Code 19”, a country for which my manual version does not identify – as you will read, that version of the bike has no running lights other than at the rear brake-lamp, speedometer illumination, and a position light indicator – I will elaborate on how to wire a tach on that version where appropriate too! ;) ]

First, let me start with this suggestion… go to your local “pull-your-own-part” automotive recycling yard (or similar) and search for a 4 pole (wire) wiring connector (a joint that has BOTH sides of the connector with about 2 inches (5cm) of wiring on each side) and use it for your installation - one side to the wiring harness, and the other to the tach lead. (And if you want to pay attention to even FURTHER detail, note that the bike main harness has all male sides of the connectors branching from it… so you can emulate this degree of “OEM detail” and hard wire the male side of the connector to the harness! ;) ) The purpose in putting a connector into this installation is for the case that if you ever need to service the bike to a significant degree, you will have an OEM appearing joint that you can easily disconnect (rather than dismounting the tach from the handlebars and having to un-route the tach lead from the frame of the bike). Pay attention you are keeping the wiring properly continuous through each side of the connector.

And one other preemptive suggestion – you should be connecting all wires into the wire harness just at the front of the driver’s seat, right at (“above”) the carburetor because this is the most forward point where all the wires you need are at in the main harness [with exception to the “Country Code 19” bike]. The harness routes from the fuse block forward. There is a connector at the carb that branches off the main harness that feeds/connects (on all models) the Engine Stop Switch, Starter Button, Front Break Light Switch, and if bike is so equipped on other models, the Lighting Switch. Two of your connecting wires terminate in this branching connector, while the other two remain routing forward in the main harness.

Tachometer Red Lead – connect to Orange Wire with Blue Tracer on bike

Tachometer Blue Lead – connect to Gray on bike (note to all – the tach blue wire can be connected Orange Wire with Blue Tracer on any bike BUT know that if you have a lighting switch on your bike, the tach light will not turn off with the rest of the running lights/instrumentation light – further description follows) [Specifically on Country Code 19 bikes, connect this lead to the Orange Wire with Blue Tracer wire – the “running light” circuit on your bike, as mentioned before, powers only your speedometer light, your brake-lamp “running light”, and a position light on the front of the bike, and this Orange/Blue tracer wire is routed more directly to these three lamps]

Reason for both above connections (please reference the wiring schematics with the following description) – When Ignition Switch is in the “ON” position, solid Orange (fused only by the Main Fuse before the ignition switch) wire supplies power to fuse 3, fuse 4, and fuse 5 at fuse block. Fuse 5 powers the Orange Wire with Blue Tracer, which is the “Ignition On” circuit (also reference instructions for the tach) for the lights/instrumentation, and it also is the power feed for running lighting circuit (Gray wiring) by one of two means. One way is through a “Lighting Switch” (on bike versions that have such a switch, which controls running lights and the headlight separately), or, on bikes without a lighting switch, jumper wires replacing the switch that allow always-on running lights and always-on headlights, [including “Country Code 19,” even though the wiring is routed further forward on the bike)]. (And, for everyone’s information, if you trace the wiring even further, you will find the Gray Running Lighting circuit [Orange/Blue Tracer for “Country Code 19”] further feeds the Brake-Running-Light and Position Light (if so equipped) circuit (brown wiring) when the ignition switch is in the On (Run) position.

In other words, this is because some countries allow the operator to control the running lighting and headlights on the bike, but in other nations (like in the United States) it is law that a motorbike have its’ running lights and a headlight on at all times that the bike is running. So in this case the lighting switch is eliminated and is replaced by “jumper” wires to complete the connections permanently. And there are two jumpers because the running lights are a separate circuit from the headlight, but both are otherwise controlled by the 3 position Lighting Switch (1. all lights off, 2. running lights on (circuit1), 3. running lights (circuit 1) and headlight (circuit 2) on).

So, if you notice, the factory fuse description of fuse 5 “tail light” is really not accurate. This one fuse actually powers all running lights (on truly ALL models).

So in summary for these two connections, when the ignition is “on”, since there is always MAIN FUSE PROTECTED power on the Orange/Blue wire (“Ignition On” circuit), this is where the Tachometer Red lead connects. And, since further “downstream” Gray wiring powers all running lights on the vehicle, the Tachometer Blue lead should connect to the Gray – so that it’s light turns off/on with other running/instrument lights on the bike if there is, in fact, a switch. (So, again, on any bike that does not have the “Lighting switch,” an alternative is that you may connect both red and blue Tachometer leads to either the Orange/Blue wire or the Gray.)

Tachometer Black Lead – connected to Black Wire with White Tracer on bike

Reason – Black Wire with White Tracer is Universal Ground (Including ground for ALL lighting on the bike – all shown traced directly to battery negative terminal)

Tachometer Green Lead – connected to White negative terminal of coil

Reason – Green Lead has to connect to negative terminal of coil (as otherwise stated in other previous postings)
NOTE: there are 2 white-wire circuits in total on this bike – one for the negative coil and the other for the headlight “low beam” circuit. Depending on where in the wiring harness you are tapping, you may need to pay attention to which white wire you are connecting to! (easy to tell – if you turn the Ignition Switch to the “On” position (and Lighting Switch “On,” if appropriate) and the dimmer switch to the “Lo” position, and a 12V test/light show’s power on whatever white wire you are probing, you have the WRONG wire).


Here is a summary, if you will:
Tach Red – Orange/Blue Tracer (Ignition “On” circuit that powers Instruments/Lights)
Tach Blue – Gray (Running lights circuit powered by above circuit)
Tach Black – Black/White Tracer (Universal Ground)
Tach Green – White connected to Coil Negative (Igniter spark “signal” to Ignition Coil)


Anyway, I hope this helps and maybe helps/improves everyone’s tachometer installations! (I guarantee there will be no horn-tone variance issues with this wiring!)

Paul Pronti

P.S. Notes:

In response to Quimrider’s submission about how much current the tach draws (Aug 15, 2007):
The tach’s “Ignition on” circuit draw’s .06 A.
The tach’s Illumination “Lamp On” circuit draw’s .12 A.
Total current required for BCS# 33-3910 tachometer is approximately .2 A (not sure if BCS is the manufacturer, but that is what the number is on the box)

In response to trykemike’s submission about voltage drop when pressing his horn (Aug 22, 2007):
You will not see a voltage deflection with what you have described. Voltage is constant from a battery (for the most part – unless you are drawing more Ah than the battery can provide, in which case yer gonna kill the battery). However, you may see some current draw fluctuations, if you know how to measure that (note that it is different than measuring voltage – you measure voltage drop across a load, current is measured in-line in the circuit – you have to disconnect whatever circuit it is you want to know how much current is there and complete the circuit through the ammeter – feel free to ask further questions if you don’t understand what I mean).

[Easy Rider]

Hey Guys (and Gals):

In response to trykemike’s submission about voltage drop when pressing his horn (Aug 22, 2007):
You will not see a voltage deflection with what you have described. Voltage is constant from a battery ........

Hey, welcome. Good post, for anyone who is into that much detail. I think there are a couple here that ARE.

Gotta comment on the above statement though. Voltage is relatively constant AT the battery, assuming we aren't talking large loads, like the starter running but............the voltage may NOT be constant at the other end of a wire.....after it goes through connectors, fuses, wires, switches, etc. as all of those things have a little resistance that often causes a small voltage drop. It is usually not significant though.

[ppronti]

Easy:

I 100% agree with you except I’m not sure what you mean by voltage may not be constant at the other end of a wire. But I do believe what I was trying to convey was the same idea. All components of a circuit including connectors, fuses, switches, buttons, and yes you are correct even about wire itself, etc… these things all have resistance, but for the most part, these resistances should be negligible values – if they aren’t negligible, there is a problem – corrosion or something.

If the individual reflects on their electricity class (or even a general introductory class in physics), V=IR (Voltage = Current (Amps) * Resistance (Ohm)). Voltage is a measure of electric potential, or a loss thereof when across a load. In an automotive (or likewise, motorbike) application, Voltage at the battery remains “constant.” Any automotive lamp/horn/speedometer/other load (in the GZ250 diagram we should be messing with) is rated for 12 V. If one is experienced with electrical systems of automobiles, motorcycles, etc., it is generally (if not absolutely) the case that most circuits have their respective loads (resistance) wired in parallel (for example, all lights should see the same battery voltage drop from one side of the load to the other). And automotive parts are generally built robust enough so that corrosion, and any potential-loss effects thereof, is minimized. So practically speaking, one generally should not need to check for small voltage drops in automotive applications, (with exception to finding out if there is corrosion or other circuit discontinuities) – which is why text lamps are available and so widely used – either there is 12 V potential available or there isn’t (an indicator light is on or off).

What does (more often than not) vary when we add/remove components in an automotive application is total current draw.

Any individual load requires a certain current draw. Since V=IR, and V remains constant (and most loads in automotive applications remain fairly constant), when you add a component (like our tachometer), you effectively reduce the value of R because you are adding a path for current to flow (if anyone wants to talk/understand this concept you can look up “parallel circuits” and the “effective/total resistance” thereof or ask here). So then the overall R goes down and thus the current draw goes up. Literally, every load in a parallel circuit requires a certain current draw.

[Water pipe analogy – it’s like taking a 6” pipe, cutting a section out of it, and using two 2” pipes to connect, the “resistance” would be seen at the 2” pipes. Adding another 2” pipe in PARALLEL would increase the amount of water (analogous to the amount of current draw in the electrical circuit) to flow.]

[The following is an example – they are not real numbers] If you have 5 lamps in your running lights system and each requires 1 A of current, total current draw for the five lamps is 5 amps. If we add our tachometer lamp circuit, in parallel (which is what I am offering suggestion to do), the total current draw for the running light circuit is 5.12 A because the tach light requires .12 A. (This current draw would be measured, in line/series, AFTER the “Ignition On” connection for the tach).

Anyway… probably boring people to death… and killing a lot of time… lol…

[Easy Rider]

Easy:

I 100% agree with you except I’m not sure what you mean by voltage may not be constant at the other end of a wire.

Anyway… probably boring people to death… and killing a lot of time… lol…

Yes, methinks you should have stopped at the first paragraph !! :roll:

By the time you reach the end of a wire (or circuit) that is farthest from the battery, the voltage WILL vary a bit depending on how much current you are drawing. The voltage of the battery remains (essentially) constant but the voltage at the far end doesn't.

For most things, that is insignificant BUT for high current devices, like headlights, it is NOT insignificant. Folks have discovered that they can get a little more illumination even from the stock lights by using heavier wire and a relay. That is required for aux. lights that you add because the "engineered" wire, switches, etc. won't handle the additional load, without overheating and making smoke, that is. :shocked:

Thus, a small voltage drop may not mean there is a problem.......if the circuit serves a high current device.

I have forgotten why this specific discussion started so........that is usually a good clue that it is time to let it die !! :biggrin:

[alanmcorcoran]

Hey Paul,

Although I will never use* any of the information you posted I am glad you took the time to do the research and post it. The best thing about the internet is that experts like yourself can choose to share their knowledge and the rest of the world can benefit from it at no cost. As someone that lived most of their life without the Internet, this is a very helpful development!

I have an old 52" DLP TV in my bedroom that I had written off as too expensive to fix until I found step by step instructions on the Internet complete with photos and part numbers. Took me two tries to get the right colorwheel for my model, and I had to nearly completely dismantle the thing to install it, but after less than an hour of screwdriving, I was back in business!

*Not that I think it's wrong: I just don't think a tach is worth the effort. I got one on the Strat but I rarely look at it. I think I know when I need to shift based on the feel/sound of the transmission. Don't think you can redline a GZ and the Strat would have to be doing about 150.

[ppronti]

Alan

My interest in doing the research on this project was actually rooted in the issues I have had with this bike since I have bought it – knowing that the previous owner had confessed (over a not-quite-running-properly bike) that he had opened the bottom of the carburetor. With my technical background I figured, “eh… you’ll figure it out.” So I bought the bike for what, now I realize in hind-site, was more money than I should have offered… it has had a snowball of issues – head gasket blew (just completed that work), chain/sprockets/front brakes are shot (getting parts for those now), and here soon I will be getting on the carb again (as I work on the drive).

So, with a bike that isn’t tuned properly, I bought the service manual and as I also perused the many contributors work on this forum over the past year about the carb, I came across the tach mod and said to myself $50 was an inexpensive way to be able to know what the engine RPM is to be able to tune the bike – and even set the idle speed.

And as I further read the issues with the installation of the unit (horn tone fluctuations, I decided to understand the schematics) – I actually took some photocopies of the schematic from the service manual and a 30 color marker set, and colored-coded the tracings of the wires accordingly – otherwise the schematic was daunting to me (I learned a lot from doing this – if I run into a schematic like this again, I may not need to revert to my Kindergarten-skills!). So really, the motivation in doing the research was selfish.

As I am a technical person, I like having a tach on an engine… it helps troubleshooting in general. I felt the 10ish hours reading the schematic an investment and would eliminate downstream issues in pulling current from the wrong place (didn’t want horn, or any other, fluctuations.

And, since I did the work, and you all have helped me before you knew me (thank you all), I wanted to “give back.”

[burkbuilds]

Great post, lots of helpful info! I bought this tach for my GZ but never installed it. After reading this post, I put it on my Vulcan 500 and it works great! Thanks for the info, even though some things were different, the overall information was a big help. I found the power source from the speedometer light and connected my power leads there, grounded to a grounding terminal under my tank and hooked the green wire up to the negative terminal on one of my coils and it seems to be working accurately! I'm idling at 1250-1300 which is specs for my bike, and I hit 4000 rpms in 6th gear at 55 mph, 5000 rpms at 70 mph. Thanks again for the helpful post!

[whitelightning]

is this the right tachometer for my bike even though it works on twin or single cyl?
http://cgi.ebay.com/ebaymotors/HONDA-KA ... ccessories (http://cgi.ebay.com/ebaymotors/HONDA-KAWASAKI-SUZUKI-YAMAHA-250-CHROME-TACH-TACHOMETER_W0QQcmdZViewItemQQ_trksidZp4634Q2ec0Q2e m14Q2el1262QQhashZitem2302dda9bbQQitemZ15037193669 9QQptZMotorcyclesQ5fPartsQ5fAccessories)
asked the seller if this would work on my bike he said............."if your bike is a dual fire ignition system, you hook the tach to the negative terminal on the coil"
what do you think? :??: :??:

[Sarris]

Yeah, that's the one, but it's only $49 here: Tachometer (http://www.powersportsoutletstore.com/product/33-3910)

This is where I purchased mine. Very easy to intall and works perfectly.

:)

[GEREN]

Any issues with dual-fire tachos?
http://cgi.ebay.com/ebaymotors/CHROME-M ... ccessories (http://cgi.ebay.com/ebaymotors/CHROME-MINI-TACH-TACHOMETER-FOR-HONDA-WITH-CLAMP-VTWIN_W0QQcmdZViewItemQQ_trksidZp3286Q2em63Q2el117 7QQhashZitem33554f058fQQitemZ220474574223QQptZMoto rcyclesQ5fPartsQ5fAccessories)

[Sarris]

None.

[GEREN]

K. Not questioning anything but wanting to make sure: The one you posted a linked for, Sarris did say single fire on the tach description.
The ones I'd readily have access to say strictly dual-fire V-twin engines only. And another one says they're for Harleys!
Exact same design though.

So there wouldnt be any issues with the above mentioned tach on a GZ250??

[Quimrider]

K. Not questioning anything but wanting to make sure: The one you posted a linked for, Sarris did say single fire on the tach description.
The ones I'd readily have access to say strictly dual-fire V-twin engines only. And another one says they're for Harleys!
Exact same design though.

So there wouldn't be any issues with the above mentioned tach on a GZ250??
it was a typo on their page. it is not a single fire tach. it is a dual tach. Apparently they have fixed the error since it no longer says single fire Harley.

[b1pig]

great writeup!
i actually saw that tach a few months ago and thought it would work great, but i didnt have the money (or wifeies cinfidence) to tackle it. talked to her about it today....


lori says:
I don't think I need that
bj says:
... well.... i do....
bj says:
just not now
lori says:
why ?
bj says:
helps keep tabs on the engine...
bj says:
plus, it adds that next little thing that makes it "feel" more like a bigger bike.
bj says:
just because yours is a beginner's bike doesnt mean you cant have the features of the bigger and more expensive bikes. you already got a windshield and saddle bags.
bj says:
just something to keep in mind. i thought it would work. glad someone tried it before me.
lori says:
true
lori says:
more wt takes away from speed


how do you argue with that????

[Easy Rider]

how do you argue with that????

I find this truly hilarious.

The guy wants bling......and the gal is trying to be more practical.
What a role reversal. :biggrin:

[zenbutcher]

hahaha... and did you notice that the only she agreed with was "glad someone tried it before me."... and she's like, "true."

[Water Warrior 2]

I would never add bling to a bike. Bling subtracts space dedicated to so many other needed items. Been adding needed items for over 4 years and still not finished. :lol:

[b1pig]

not so much "bling" as "function"....

i want to add the tach and a couple other little nic-nacs. she's the saver... i'm the spender. :)

[Water Warrior 2]

Functional is good. Makes any ride just a little better.

[5th_bike]

talked to her about it today....


lori says:
I don't think I need that
[etc. etc.]
lori says:
more wt takes away from speed


how do you argue with that????

Simple.

bj says:
Honey, come off it, it weighs as much as a cell phone. Less than a glass of water.
You're telling me that you actually skip a meal and go to the bathroom before you ride, because less weight will make you go faster?

It's very handy to adjust idle rpm to 1300...
Also, the engine should preferably be operated at revs higher than 3,600 rpm - so it's a great and very useful thing to add.

Just don't stare at it while you're riding.

[Easy Rider]

how do you argue with that????

Simple.

Wait just a sec.............
That tells me just one thing: 5th_bike obviously is NOT married !!! :roll: :crackup

[5th_bike]

[quote="5th_bike":lcuvkspa]
Simple.

Wait just a sec.............
That tells me just one thing: 5th_bike obviously is NOT married !!! :roll: :crackup[/quote:lcuvkspa]

You're right. At least, concerning my blatantly erroneous "simple" statement... :whistle:

[Palaka]

Anyone know of a good place to get a single fire tach that is not to expensive. It seems all the ones I find it doesn't say or if it does they cost $200+.

[Sarris]

Read the first post on this thread. Where to buy and how to install. I have one, it works great.

:2tup:

[Palaka]

the store is closed now :(

[Sarris]

Here is one on eBay for the single cylinder Savage 650. This one should do the trick. No problemo.

It looks exactly like the one I put on my GeeZer. It's $69.99 Tachometer (http://cgi.ebay.com/ebaymotors/SUZUKI-SAVAGE-LS650-S40-CHROME-TACH-TACHOMETER-SALE-/220647575410?pt=Motorcycles_Parts_Accessories)

:2tup:

[Palaka]

sweet thanks

[Easy Rider]

Anyone know of a good place to get a single fire tach that is not to expensive.

I'm pretty sure the GZ fires on every stroke, not just the power stroke, and that is called double fire.

A single fire tach only expects to see a spark on the power stroke and would read 2X the actual RPM.

[alantf]

I'm pretty sure the GZ fires on every stroke, not just the power stroke,

So why would ANYTHING want to fire on the exhaust stroke? Just seems pretty pointless on the designer's part, designing something more complicated with no use whatsoever! :cry:

[blaine]

Anyone know of a good place to get a single fire tach that is not to expensive.

I'm pretty sure the GZ fires on every stroke, not just the power stroke, and that is called double fire.


:plus1: Yes, The G.Z. fires on every stroke, Duel fire ignition.I think it has to with the design of the ignition module.

:tup:

[alantf]

I think it has to with the design of the ignition module.



So what you're saying, right, is that the designers can't design shit? I don't think I'd admit to designing anything so totally useless. :??: :cry:

Surely, if you're being paid to design an ignition module, you'd design one that fired only on the ignition stroke, which is the only place it's needed. O_o

[Easy Rider]

Surely, if you're being paid to design an ignition module, you'd design one that fired only on the ignition stroke, which is the only place it's needed. O_o

Yes but it is cheaper, simpler and more reliable (fewer parts) if you just let it "sync" with the piston and fire every time it approaches TDC. :cool:

Having a spark at TDC on the exhaust stroke really doesn't DO anything useful.......but it can cause some interesting back-fires if the mixture gets really rich or the valve timing gets out of whack. :cry:

[Quimrider]

Like Easy Rider said, It's far more simple and cheaper to do dual fire ignition. If you wanted to do single fire you would need a cam position sensor so the ignition module can tell the difference between TDC of the combustion stroke and TDC for the exhaust stroke. Remember in a 4 cycle engine the piston only fires once every two revolutions.

[alantf]

Like Easy Rider said, It's far more simple and cheaper to do dual fire ignition. If you wanted to do single fire you would need a cam position sensor so the ignition module can tell the difference between TDC of the combustion stroke and TDC for the exhaust stroke. Remember in a 4 cycle engine the piston only fires once every two revolutions.

I remember in the old days, working on cars with the old fashioned mechanical breakers, that had to be changed every few thousand miles. They worked fine (until the contacts started pitting), so I would have thought that in this day and age, someone would have come up with a cheap solid state version that would do the same thing, but in a better way. :??:

[Palaka]

WOW look what I started :hide:

[alantf]

WOW look what I started :hide:

That's what makes this site so much fun. :)

[Water Warrior 2]

The simple and cheap design is reliable and is probably a lot more desired in 3rd world countries where the GZs are a primary transport device. The GZ is what it is and we are actually served well by it. The KISS principle is alive and well.

[Quimrider]

I remember in the old days, working on cars with the old fashioned mechanical breakers, that had to be changed every few thousand miles. They worked fine (until the contacts started pitting), so I would have thought that in this day and age, someone would have come up with a cheap solid state version that would do the same thing, but in a better way. :??:

They have :) They've replaced the mechanical complexity of the gears driving a distributor with a Hall effect or VR sensor on the fly wheel that tells the magical electronic ignition box when the piston is at TDC. Following the KISS principle we don't care whether it's on the combustion stroke or exhaust so we'll just fire the plug on both. If we did care we'd have to violate the KISS principle and add a cam position sensor to determine when the piston is at TDC on the power stroke. This does have some advantage when it comes to multi-cylinder engines and fuel injection.

The magical electronic ignition box takes care of ignition advance based on rpm. On more advanced systems there might be a throttle position sensor that combined with RPM can calculate engine load and adjust ignition advance accordingly. You could get more fancy (accurate) measuring engine load by adding a manifold air pressure sensor to the sensor mix. This magic in the ignition box replaces the vacuum advance or centrifugal advance from distributors of yesteryear :)

So essentially a cheap crank position sensor and electronic box replace the old school distributor.

[Sarris]

Just get the one on eBay I suggested. Its for the single cylinder S40 nee Savage 650.

It will work fine because which ever it is (single or dual fire, who cares really??) it fires the same as the GeeZer.

:)

[Palaka]

that works for me appreciate everyones help

[Quimrider]

I tried to make the following edit to the main post, but got a database error. I sent the admin an email. I found the tach elsewhere for a pretty good price. I"m buying one for one of my bikes.

[strike:34jpz9ly]About 57 dollars after shipping. [/strike:34jpz9ly] This is not a fancy
tach. just a plain and simple 8K RPM tach.

Update 08/17/10: Powersportsoutletstore.com has entered the dustbin of history.

I found what appears to be the same tach at BKrider for $39.99 + $8 and change shipping. (http://www.bkrider.com/bkrider/skusearch_v3.asp?scriteria=C01160541)

[5th_bike]

Regarding the smaller (1 7/8 " diameter) tach, Dennis Kirk still exists but at the tach they mention "This Product is No Longer Available"

They still have similar ones, for $99.99. A bit steep.

http://www.denniskirk.com/jsp/product_c ... Id=&mmyId= (http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=408088&store=&catId=&productId=p408089&leafCatId=&mmyId=)

If you want one please search for "Drag Specialties 1 7/8 Tachometer"

[Quimrider]

Regarding the smaller (1 7/8 " diameter) tach, Dennis Kirk still exists but at the tach they mention "This Product is No Longer Available"

They still have similar ones, for $99.99. A bit steep.

http://www.denniskirk.com/jsp/product_c ... Id=&mmyId= (http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=408088&store=&catId=&productId=p408089&leafCatId=&mmyId=)

If you want one please search for "Drag Specialties 1 7/8 Tachometer"

or just click on the link in my post above. :retard: but, that's for the 2 9/16" diameter gauge. I have one of the smaller tachs that goes up to 12K, It's too small to get a good reading at a glance.

[Water Warrior 2]

I tried to make the following edit to the main post, but got a database error. I sent the admin an email. I found the tach elsewhere for a pretty good price. I"m buying one for one of my bikes.

[strike:18gweuzu]About 57 dollars after shipping. [/strike:18gweuzu] This is not a fancy
tach. just a plain and simple 8K RPM tach.

Update 08/17/10: Powersportsoutletstore.com has entered the dustbin of history.

I found what appears to be the same tach at BKrider for $39.99 + $8 and change shipping. (http://www.bkrider.com/bkrider/skusearch_v3.asp?scriteria=C01160541)
I wonder if the tach from BKrider would work on Lynda's M-50 ? Looks pretty nice from the pics and she would probably love to have it.

[blaine]

I wonder if the tach from BKrider would work on Lynda's M-50 ? Looks pretty nice from the pics and she would probably love to have it.

Nice looking tach,I don't see any reason why It wouldnt work on the M-50.
:rawk: :2tup:

[mrlmd1]

If you want to go a different route, ie, a small electronic tach + hour meter, look at Tiny Tach.
http://www.tinytach.com/tinytach/index.php
They can be bought for as low as $40 from eBay and Amazon and other places, are easy to hook up with an inductive coil wire wrapped around a spark plug wire, have an internal battery supposedly guaranteed for 5 years and are totally waterproof, small enough to be mounted anywhere. I saw them on a jetski forum and another bike forum and they seem to work just fine.

[Water Warrior 2]

I wonder if the tach from BKrider would work on Lynda's M-50 ? Looks pretty nice from the pics and she would probably love to have it.

Nice looking tach,I don't see any reason why It wouldnt work on the M-50.
:rawk: :2tup:
Note to self. E-mail for more info.

[hacc81]

Great How To!! I received my tach today (drag specialties) and following the instructions and this post I finished the installation in less than 30 minutes!!
Thanks Quimrider for writing this post in the first place and for everyone who added some good details and reminders... It was a great help for newbies like myself...
Unfortunately, I could not take her for a ride to test the tach cause today it's snowing here in Abbotsford... Bummer! Hope tomorrow the weather is a little better though...
Cheers and safe riding all!

[Water Warrior 2]

And of course we are expecting a forthcoming pic of said tach to entice the rest of the members. :2tup:

[hacc81]

Hey Water Warrior, as requested, here are the photos of the tach fully installed...
As I already mentioned, it's been snowing here so I haven't been able to ride the bike :cry:, but I started the bike to test the tach and it works great!!...
I know that it looks big but it's quite nice actually! :cool:

[attachment=0:1bjqkwaw]DSC09188.JPG[/attachment:1bjqkwaw]
[attachment=2:1bjqkwaw]DSC09182.JPG[/attachment:1bjqkwaw]
[attachment=1:1bjqkwaw]DSC09186.JPG[/attachment:1bjqkwaw]

[jonathan180iq]

That's awesome!
Well done.

[Water Warrior 2]

Right on. The tach looks great. I like the size, easy to see at a glance too. I wonder if I sneek one of these onto Lynda's M-50 without her catching me in the act.

[Water Warrior 2]

Hacc81, just to make it easy for an old guy, where did you get the tach and how much was it, cost, shipping and all the other stuff involved ?

[hacc81]

Hacc81, just to make it easy for an old guy, where did you get the tach and how much was it, cost, shipping and all the other stuff involved ?
Hi Water Warrior, I bought it from this guy in LA: http://cgi.ebay.ca/ws/eBayISAPI.dll?Vie ... _500wt_922 (http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=120684896914#ht_500wt_922) (I know that the photo is different, but he assured me that it was a Drag Specialties, and it was)...
And the shipping depends on how fast you want it at your house... I paid like US$25 for 2 days shipping... But I think if you have the patience you could arrange cheaper shipping. He provided great customer service and replied to all my questions fairly quick.

[tcrave]

http://cgi.ebay.com/ebaymotors/Custom-M ... ccessories (http://cgi.ebay.com/ebaymotors/Custom-Mini-Electronic-Tachometer-Gauge-Harley-_W0QQcmdZViewItemQQhashZitem20b90407b5QQitemZ14054 3002549QQptZMotorcyclesQ5fPartsQ5fAccessories)

does anyone know if that one will work? If so, I think I am going to get it. I don't want to buy it if it won't work, though. Says its for Harleys...but looks like it is the same thing as people are posting on here.

[blaine]

http://cgi.ebay.com/ebaymotors/Custom-Mini-Electronic-Tachometer-Gauge-Harley-_W0QQcmdZViewItemQQhashZitem20b90407b5QQitemZ14054 3002549QQptZMotorcyclesQ5fPartsQ5fAccessories

does anyone know if that one will work? If so, I think I am going to get it. I don't want to buy it if it won't work, though. Says its for Harleys...but looks like it is the same thing as people are posting on here.
Yes,it will work. :2tup: :)

[tcrave]

http://cgi.ebay.com/ebaymotors/Custom-Mini-Electronic-Tachometer-Gauge-Harley-_W0QQcmdZViewItemQQhashZitem20b90407b5QQitemZ14054 3002549QQptZMotorcyclesQ5fPartsQ5fAccessories

does anyone know if that one will work? If so, I think I am going to get it. I don't want to buy it if it won't work, though. Says its for Harleys...but looks like it is the same thing as people are posting on here.
Yes,it will work. :2tup: :)
Thanks! Just ordered it! :) Will post pics once I get it installed.

[tcrave]

Hey, so I have a question. I was trying to install the tach...I just put the wires to the connections and didn't solder, just incase. I turned the bike on and the needle spikes to 8, then comes back down. I tried starting it (before realizing I had the gas tank off, lol) and the needle went all over the place.

Is this normal or is it effed?

[Quimrider]

some tachs have a built in diagnostic or calibration or something like that and will go full scale when power is applied. Sounds like you got one of the tachometers that does this. Get her some gas and start it up to see if it works. You should be ok without soldering for testing purposes, but you will want to solder it for a permanent installation.

[tcrave]

oh ok, i got the one that one i linked to. I didn't want to put everything back together permanently until i knew it worked, but I suppose I'll just have to take the chance. I tried hooking it up to both the coil and the horn and got the same results.

You know, the one i got came with a little piece that connects to the handlebar like the Drag tach. I was originally planning to install it like the OP, but now that I have it on like that, I don't like it and think I will be using the handlebar thing instead. Its at such and odd angle when using the OP's method.

[tcrave]

Oh, and it turns out you really don't need to take the tank off to install the tach. The first time I tried installing it, I took the tank off, but then after I got it all back together, I realized I had soldered the green wire to the orange wire instead of the white one, so it didn't work. I really didn't feel like taking the tank back off, so I tried with it on. I was able to get the green and orange unsoldered and then resolder the green wire to the white one without taking the tank off. I was initially going to solder the red and blue wires to the coil, but decided to go ahead with everyone else's suggestion of wiring them to the horn, which doesn't require taking the tank off either.

Actually, I didn't even need solder for the red and blue wires. I just striped back the wire housing to expose about 1/2" of wire, then shoved the red wire up the female connectors hole, then shoved the blue wire up the other female connector's hole and shoved the plug back on. Seemed to work just fine. I'll take it for a ride here in a little bit and see how it goes.

And to anyone else attempting this, just to warn you, don't tighten the ground wire too much. The black wire is kinda weak and will break if you tighten it up too much. This frustrated the hell out of me the first couple times I tightened it up and it broke.

One more thing, if you don't have a volt tester or are too lazy to go get it, I found that just unplugging the horn and sticking the wires in each of the female connectors and turning the bike on is a great way to figure out which is + and which is - . Well, if the tach lights up and the needle jumps to 8 and then goes back down when you switch the bike on, its the right one, if not, its the wrong one. And its a faster way to do so too! lol

I'm glad I finally got it installed, but damn that needle bounces a lot. I'm used to my car though that idles pretty smooth most of the time. Kinda funny, my car has 209,000 miles and still idles smoother than my bike that has 6,000 miles. This also makes me think I need to run some more seafoam through the carb.

[tcrave]

Come to think of it, when you said to wire it to the horn, did you mean both red and blue wires or just one or the other? I assumed both wires.

[Quimrider]

yes both red and blue.

[grego]

hi all

today i installed the tach.. took me about 2 hours cause i'm anal. i didn't take the tank off because everything was accessible. the red and blue i ran inside the sheathing took the plug apart and soldered the wires to the back of the connector. removed the shrink on the neg at the coil soldered the green wire to it and installed new shrink all the way up to the harness. did the same to the ground going to the coil mount. checked out the tach. according to all that i have read i'm 500 rpm higher then everybody else. at 25 mph=3000,20 mph=3500.... don't ask me why cause i couldn't tell ya, but perhaps someone could inform me as to why i'm 500 higher then the rest of the world..

safe biking

grego

[tcrave]

grego- just shift earlier I suppose, thats what I am doing. My bike is doing the same thing, but I'm just shifting earlier than i used to to keep the RPMs down a bit better. It took me a little longer than 30 min only because I solder the wrong wires by accident the first time.

Also, I noticed right after I installed the tach that for some reason my trip meter kept screwing up, it kept advancing itself unexpectedly and was all around screwy. After a couple days of irritation, I figured out that by installing my tach, my clutch cable was rubbing against my trip knob when I turned left. Problem solved though, I ended up just zip tieing it to get it out of the way, I'll take a pic next time I get a chance. I think the reason I was having this problem and others weren't was because I decided to install it on the left side instead of right. The tach on my car is on the left so I wanted to keep it consistent.

One thing I don't like about the tach though is when the sun is shining behind me, I get a lot of glare from it...not sure how to fix this yet.

[Water Warrior 2]

LOL. Always ride towards the sun. I get the same thing with the speedo on my bike. Reflections happen.

[bwader]

For a cheaper digital alternative. This digital tach/ hour meter works pretty good, though it does have a few seconds lag. I have had 2 of these one for over a year until the battery died, then the last one I got it worked fine for 80 scooter hours and 3,000 miles when it started to malfunction.

I'm buying another one. I just use zip ties to mount and it has its own battery and has two wires. One wire you literally wrap around the insulated part of the spark plug wire and the other end you connect to ground or to the frame. Very simple and easy to mount and use.

http://www.ebay.com/itm/Digital-Hour-Me ... 2a2f2c230c (http://www.ebay.com/itm/Digital-Hour-Meter-Tach-Tachometer-Gauge-Spark-Plugs-Engine-Motocycle-Boat-/181180048140?pt=LH_DefaultDomain_0&hash=item2a2f2c230c)

It can be set for 2 stroke or 4 stroke engines. I had one on my 2 stroke motorized bicycle and 150cc scooter last year. You can every engine you own and it keeps track of the hours, rpms, and service time due you set.

I'm going to order another one for my GZ.

I do say that analog tachometer looks sharp on the GZ!

[bschift]

For a cheaper digital alternative. This digital tach/ hour meter works pretty good, though it does have a few seconds lag. I have had 2 of these one for over a year until the battery died, then the last one I got it worked fine for 80 scooter hours and 3,000 miles when it started to malfunction.

I'm buying another one. I just use zip ties to mount and it has its own battery and has two wires. One wire you literally wrap around the insulated part of the spark plug wire and the other end you connect to ground or to the frame. Very simple and easy to mount and use.

http://www.ebay.com/itm/Digital-Hour-Me ... 2a2f2c230c (http://www.ebay.com/itm/Digital-Hour-Meter-Tach-Tachometer-Gauge-Spark-Plugs-Engine-Motocycle-Boat-/181180048140?pt=LH_DefaultDomain_0&hash=item2a2f2c230c)

It can be set for 2 stroke or 4 stroke engines. I had one on my 2 stroke motorized bicycle and 150cc scooter last year. You can every engine you own and it keeps track of the hours, rpms, and service time due you set.

I'm going to order another one for my GZ.

I do say that analog tachometer looks sharp on the GZ!

This looks like a very easy and inexpensive solution. Has anyone else tried it?

[5th_bike]

Haven't tried it but my analog one is still going strong after almost six years and more than 8,000 miles.

It seems that the ones bwader was talking about give up after one year or 3,000 miles, whichever comes first...

Ebay also has a lot of analog tachometers for $10 to $75, search for "tachometer motorcycle".

[wacio]

I'm looking at my options to install tach. I did go thru the schematic and found potential source of power in the front headlight that does not require modification of the wiring. There is unused power connector that appears to be for powering front parking light (not connected in US version). It is always on with ignition on, same circuit runs rear taillight (brown wire). Second wire in the connector is ground (black with white tracer). The drawback is that this is powered also when ignition switch is in parking light mode, but not too many would use this mode anyway.

Picture below is the schematic:
http://www.gz250bike.com/forum/picture.php?albumid=54&pictureid=325

This is part showing headlight with spare connector outlined red:
http://www.gz250bike.com/forum/picture.php?albumid=54&pictureid=326

This is picture of the inside of headlight:
http://www.gz250bike.com/forum/picture.php?albumid=54&pictureid=321

Described connector:
http://www.gz250bike.com/forum/picture.php?albumid=54&pictureid=324
http://www.gz250bike.com/forum/picture.php?albumid=54&pictureid=322
http://www.gz250bike.com/forum/picture.php?albumid=54&pictureid=323

[5th_bike]

The easiest source of power is the yellow/green wire at the horn. Is also close to the coil.

[wacio]

The easiest source of power is the yellow/green wire at the horn. Is also close to the coil.

Thank you. Yes I agree for the +12V. Where do you get good ground from that's nearby though?

[alantf]

Look for a black/white cable. That's the colour of the ground cables.

[5th_bike]

Alantf is correct about the black/white wires being 0V.

The frame is also connected to 0V. As far as I remember, I squeezed the tach's zero volt wire under a nut at the coil, to connect to the frame.
You'll have to connect to the coil under the tank anyway.

[wacio]

Thank you all. I got the tach going. Works great. I used cheapo ebay 13k rpm tach.

http://www.gz250bike.com/forum/picture.php?albumid=54&pictureid=327

Its mounted using screw mounting turn light bracket.

[amgarb]

I've read all 12 of these pages but many of the links and pictures are dead and gone.

I bought an ebay tachometer like the one pictured directly above but the wiring description for mine a a bit vague and I'm hoping to get a bit of help.

I have 5 wires and here is how I think they get connected:

1. Long Red for light +
2. Long Black for light -

3. Short green - ground
4. Short black - power to tach
5. Short yellow - signal

So I thing the long red and short black can be connected to power at the horn.

Then I connect the long black and the green to the frame some place.

Finally, hook the yellow wire to the coil but I'm not sure which side.

Can anyone advise?

Thanks!

[5th_bike]

Do not connect the yellow wire at the spark side of the coil.

[wacio]

You can try both - mine is connected to the white one.

[amgarb]

Since many of the photos from earlier in this thread are long gone, I figured I would document what worked for me.

I bought my tachometer from fleabay. It was $14 (best offer with free shipping). The description was “LED Motorcycle Tachometer Fit Suzuki Intruder Volusia VS 700 750 800 1400 1500"

http://i104.photobucket.com/albums/m168/agarb6/tach1.png

It came with no instructions and the wiring as described in the listing was quite Chinglish:
Wire Connection:
Long red- positive, Long Black- Negative
Short Green- Ground,Short Yellow/Black-Engine Signal
Short Black- power/ignition lock positive

After online research, I determined:

The long black (-) and long red (+) are for the backlight.
The short green is ground
The yellow/black is the input signal to the tach.
The short black is power to the tachometer.


So...

http://i104.photobucket.com/albums/m168/agarb6/Tachometer.jpg

I combined and extended the long red and short black and connected them to power at the horn. (Black wire in my photo below. But you can barely see it since I pierced the black tubing and threaded it through.)

I also combined and extended the long black and short green and grounded them at the coil. (Blue wire in my photo below.)

I extended the yellow/black wire and connected it to the coil. (Brown wire in my photo below.)

http://i104.photobucket.com/albums/m168/agarb6/Wiring.jpg


Fired it up and it worked. Tachometer reports 6800 rpm at 60 mph. A bit more than others report in this thread. The tach is somewhat on the slow side to respond; wish it was a bit faster.

http://i104.photobucket.com/albums/m168/agarb6/1.jpg

[Vegas Street Rider]

Great photo presentation. Others doing the same project will be appreciative.

[Water Warrior 2]

Nice How To article, My Honda has a digital graph that is stupid. Round with a needle is good.

[alantf]

Honda?.... Is the dash anything like a BMW?
BMW dash.jpg (http://www.gz250bike.com/forum/attachment.php?attachmentid=811&stc=1&d=1494253794)

[spldart]

Honda?.... Is the dash anything like a BMW?
BMW dash.jpg (http://www.gz250bike.com/forum/attachment.php?attachmentid=811&stc=1&d=1494253794)

I hath been stricken blind!

Where is the flux capacitor?!

[Water Warrior 2]

Honda?.... Is the dash anything like a BMW?
BMW dash.jpg (http://www.gz250bike.com/forum/attachment.php?attachmentid=811&stc=1&d=1494253794)
I've never looked at a BMW.
Hopefully this pic will give you an idea of the tach. There is a thin line across the display that registers revs. I just ignore it.

I also included my ancient ice pick that I used to adjust the headlight. A screw driver is supposed to do the job but I never figured out how a fat tool should fit in a very small deep hole.

[gz]

Bought this one for 40€:
https://www.louis.eu/artikel/t-t-tachometer-48mm-pos-10-000-rpm-black/10034533?list=181668280&filter_article_number=10034533

Works great. Connected the red wire for 12v power to the horn (added a fuse box with 10A fuse), black wire to the bolt between the coil terminals for ground, and the green one to the negative terminal of the ignition coil. Adjusted the number of the cylinders so it doesn't double RPM. I only need some kind of a handlebar bracket to make it look a bit better.

[alantf]

Looks like a little L shaped bracket with a hole in either end should do the trick. I reckon you should be able to pick one up at any hardware store.

[wacio]

I used screw mounting the turn light - its further to the right so not causing the tach to be mounted angled

[gz]

I used screw mounting the turn light - its further to the right so not causing the tach to be mounted angled

That's even better. Thanks.

[wacio]

Thank you all. I got the tach going. Works great. I used cheapo ebay 13k rpm tach.

http://www.gz250bike.com/forum/picture.php?albumid=54&pictureid=327

Its mounted using screw mounting turn light bracket.

I have small update. This tach lasted me about 2k miles and while running at high speed on the highway - it broke from vibration. Something internal - holding the indicator needle went loose and tach now works erratically and buzzes from time to time as rpm increases. I decided to replace it with fully digital one - also from Ebay - unit that combines digital tach and voltmeter.

https://www.ebay.com/itm/2-in-1-Motorcycle-Gauge-Meter-Tachometer-Voltmeter-DC-12V-Waterproof/133034545747?_trkparms=aid%3D111001%26algo%3DREC.S EED%26ao%3D1%26asc%3D20160908131621%26meid%3D0b10e 192cd094dd6af2b5326aadf8484%26pid%3D100678%26rk%3D 3%26rkt%3D11%26sd%3D472083223199%26itm%3D133034545 747%26pmt%3D1%26noa%3D1%26pg%3D2481888&_trksid=p2481888.c100678.m3607&_trkparms=pageci%3A1d6aa820-d1ac-11e9-acca-74dbd1803f37%7Cparentrq%3A0d5d3b6616d0a9e0a7e0fd51 ffc3630b%7Ciid%3A1

[Fatch]

How's the digital tach holding up? I'm planning to add one to my bike, too (or possibly swap out the speedo with a digital speedo/tach combo unit).

[wacio]

The problem with it:
- not bright enough to view in full sun light
- also left whole day in sun light it started to melt the blackout film that is over the segments to make the appear black.
http://www.gz250bike.com/forum/picture.php?albumid=54&pictureid=437

Please note lower left in voltage area - discoloration.

BTW: My voltage shows 10.8 volts and it is actually correct. Investigating why I have such voltage drop in the front light where I attached the meter. it is 12.3 on the battery.

[5th_bike]

BTW: My voltage shows 10.8 volts and it is actually correct. Investigating why I have such voltage drop in the front light where I attached the meter. it is 12.3 on the battery.

The voltage drop is simply from the wire resistance, your headlight draws several amperes so part of the battery voltage gets lost as heat in the wiring. To get a better reading, connect the wires closer to the battery, or on a circuit that doesn't draw much current. At the horn, the voltage only drops a bit when you honk. The yellow wire at the horn is 12V, I connected the +12V (red) wire of my tach there.

[wacio]

The voltage drop is simply from the wire resistance, your headlight draws several amperes so part of the battery voltage gets lost as heat in the wiring. To get a better reading, connect the wires closer to the battery, or on a circuit that doesn't draw much current. At the horn, the voltage only drops a bit when you honk. The yellow wire at the horn is 12V, I connected the +12V (red) wire of my tach there.

Not connecting it to headlight bulb wiring. I'm using brown wire that was some option in harness - also in the headlight enclosure. From schematic it does not seem to be connected to anything else...

BTW: Checked voltage at the horn - its 11V. Maybe my ground somewhere is weak

[alantf]

European bikes have a 5w parking light along with the headlight, so this could be the unused wire that you see in the headlight bucket.

[5th_bike]

Not connecting it to headlight bulb wiring. I'm using brown wire that was some option in harness - also in the headlight enclosure. From schematic it does not seem to be connected to anything else...

BTW: Checked voltage at the horn - its 11V. Maybe my ground somewhere is weak

I got similar readings as you did, a lower voltage at the horn than at the battery itself. Considering the measurement was taken with the lights on (can't switch them off, US bike), I'd say the horn circuit and the other ones like the brown wire in the headlamp branch off somewhere between the battery and the lights - after the main fuse. No worries about "weak ground".

Ah well, it seems there is no other possibility to get battery voltage than at the battery itself, because the remainder of the electric circuits works under a bit lower voltage. It isn't too hard to squeeze a wire between the battery poles and clamps. Quite easy to route too, along with the wire harness under the tank. Do keep away from the hot engine head. And include an inline 10A or so fuse for the red wire, right at the battery.

[wacio]

I use the voltmeter to verify state of battery and charging system. I'm OK with the voltage drop as long as its normal. As long as I see normal consistent value - allowing me to verify battery state and higher voltage while running - indicating its charging, I don't think adding extra wires is worth the effort just to see actual battery voltage...

[5th_bike]

I use the voltmeter to verify state of battery and charging system. I'm OK with the voltage drop as long as its normal. As long as I see normal consistent value - allowing me to verify battery state and higher voltage while running - indicating its charging, I don't think adding extra wires is worth the effort just to see actual battery voltage...
Well it seems normal, I think it's because of the resistance of the main fuse. And, apologies for the misinformation, about 12V being available at the horn.