Just a few questions.... [Archive]

GZ Jess

06-04-2010, 02:31 PM

Here is what I have noticed about my bike after riding a couple of weeks.

It will only start if the choke is closed (pushed all the way forward) and I turn the idle screw up. Ig I touch the choke at anytime it will either not start or stall out. After it runs for less than a minute I can back the idle down half and after the first couple of blocks I back it down more.

It tends to idle very high after a stop, especially a quick one, even after I have back it way down. I notice this even more if I have ridden a longer distance/time.

If I ride the bike hard or at speeds above 45 it will back fire every time I turn it off. Why does it do this?

I think that the back firing is more common with a carbed bike but I may be mistaken.

Do you think that my choke cable may need replaced? It seems that this is kind of common on these bikes (from what I've read).

Okay thank you, any and all opinions or advice is welcome!

Easy Rider

06-04-2010, 03:00 PM

It will only start if the choke is closed (pushed all the way forward) and I turn the idle screw up.

Okay thank you, any and all opinions or advice is welcome!

How does it happen that you figured out that specific combination ??
If the "choke" is working right, it should also make the idle speed increase a bit.

NONE of that is "normal". Sounds like it is running VERY lean for some reason.
Continuing to ride it like that might harm the engine.

Is it all stock, as far as you know ??
Specifically, is there a stock air filter in place ??
A low restriction filter or an air leak around the rubber boots on either side of the carb can cause what you are describing.

A gummed up carb can cause it too. Have you run any carb cleaner through with the gas yet ??

Is this the first post you have made about how your bike runs ??
It is best to keep all of those kinds of questions together in ONE thread because they likely are all related. It looks like you are doing that; maybe it was someone else that has it spread out.

mrlmd1

06-04-2010, 04:59 PM

The idle is supposed to be adjusted on a warm engine, not to start the bike. First set that right and leave it there. If it is idling very fast at a stop after it warms up, the idle is set too high. Or the choke (an enricher circuit) may be sticking in an engaged position (too rich a mixture). The idle and choke really have nothing to do with each other and if you start adjusting more than one thing at a time, you (and anyone on here) may never figure out what's going on.
And it's hard to follow you - what is back down, the choke or the idle screw when you stop and it idles fast? I just want to be clear.
The "choke" may need to be on a little to start the cold bike, that is, the lever pulled back towards the rider, slowly pushed forward as the bike warms up until it's completely off. I assume you are operating this correctly, or are you reversing the operation and pushing it all the way forward when you start it up?

Isn't backfiring (an explosion inside the muffler) caused by an overly rich mixture?

You would benefit from carb cleaner like ER suggested and also try and lubricate the choke cable and linkage if you think this is binding.

GZ Jess

06-04-2010, 05:12 PM

Okay Easy, lets see, I had one other thread about the starting it when I first got it, since then I have notice the rest.

First off I could not get it started to save my sole. The guy had it started when my hubby went and looked at it and he turned it off and restarted fine. I tried using the choke like we do on the other bike bike but it didn't help at all. I found the screw under the seat, close to where my husband's choke is and messed with it. I noticed that it started to want to start so I moved it some more until it finally did. It has a very chug chug sound when it starts for a couple of seconds then revs very high. That is when I back off that screw. I tried giving it a little gas (and another time using the primer) before I started it as well but it just flooded.

When the bike is warm and running I have moved the choke to half to see what . It will at first rev slightly but then go back to normal idle speed.

It is an '04 and had 830 miles when I bought it. As far as I can tell it is completely stock, however :( I have not looked at the air filter, I had planned on doing a complete service on it but got to riding and forgot, I've only had it 3 weeks or so. The guy that sold it claimed to be a mechanic and said he serviced it at the beginning of the season but I don't know why you would do that and then sell it so I had intended to do it myself.

I have not run carb cleaner in it. Is seafoam a good one to get?

Thank you for your free advice I hate going to a shop and being taken advantage of. I like to have an idea of what I need before I take it.

Easy Rider

06-04-2010, 06:07 PM

Isn't backfiring (an explosion inside the muffler) caused by an overly rich mixture?

Yes....no.....maybe. :biggrin:

A real "backfire" is through the carb and is something you almost never see these days.

So, the modern "backfire" that sounds like a gun shot, is indeed caused by raw gas getting into the exhaust somehow (too rich).

A little popping on decel, which many riders call a backfire but isn't, is most often the result of a too LEAN condition. I think that's what we have here.....maybe.

Easy Rider

06-04-2010, 06:17 PM

I have not run carb cleaner in it. Is seafoam a good one to get?

Berrymans B12 Chemtool is better, I think.

And to echo what others have said:
You need to leave that idle adjustment knob ALONE when trying to start it. Opening the throttle just a tiny bit does exactly the same thing......but you should not do that when starting either, at least not until you hear it fire.

It sounds to me a lot like you have the operation of the choke backwards. Read the post just prior to this about which way is ON and which is OFF. This time of year, it should not need to be more than half ON.....but it's OK to have it full ON until it fires if you need to. After that, you should be able to listen to the engine and as it runs faster, reduce the choke just a bit.

The little beasts are cold blooded and it may take a full 5 minutes or warm up or riding before you can take the choke completely off.......and it the carb is dirty, it might take a LOT longer than that.

GZ250

06-04-2010, 11:48 PM

do you know where is the air filter, open the left side cover and remove the air filter, smell it, if it has a lot of gas smell then your choke is kind of stuck and needs replacement, oiling sometime helps otherwise it is good to replace.

all starting and firing issues come under card or plug. did you check the plug. is it clean and new. if it is old replace it it is cheap and you will have a stronger spark. as Easy said use the additive and use a little more and do not completely fill the tank that way you can have fresh gas and new additive for faster cleaning.

when the bike is real hot after 30 mins ride (running) adjust the idle then to the minimum or slightly up and your high idle issue after stopping will go away. if idle is high i experience even a bad shifting in gears on my gz.

good luck

Water Warrior 2

06-05-2010, 01:10 AM

When checking the air filter it has to be removed and visually inspected on the inside. The GZ design is kinda strange b/c the air travels from the inside to the outside of the air filter.

GZ Jess

06-05-2010, 09:19 AM

Ok I will head to the garage to check the inside of the air filter, the plug and run some carb cleaner and report back after my 3 hr ride this afternoon!

Oh and it has never backfired through the carb as described, it is just a little poof when I turn it off. The hotter the bike the louder the poof.
I do have the choke operation correct it just does not seem to help to move it half or all the way open at all.

Thanks everyone!

blaine

06-05-2010, 09:52 AM

I do have the choke operation correct it just does not seem to help to move it half or all the way open at all.

Suzuki's had a bad habit of the choke sieging up at the carb end.Dissemble with a 14mm wrench.Clean spring,plunger,and cavity.Check for proper movement of cable and reassemble.
.

up

GZ Jess

06-05-2010, 10:52 AM

Is it correct that in order to check the plug I will need to remove the gas tank. I am reading the service manual and that is all I can find related to the plugs.

Viirin

06-05-2010, 11:13 AM

The tanks not hard to remove - just a couple of bolts after you take the seat off and disconnect the fuel line - shouldn't take more than two minuets, just make sure you have a extension for the wrench you use on the bolts to raise the wrench above the tank or you might end up taking some paint off or denting your tank (like me) if the bolts were on as stiff as mine when i took it off.

Also, you'll need a 14mm socket to get the plug out if i remember correctly - i'm only mentioning this because the first time i only had a small socket-wrench kit that went up to 12mm so i could change the plug even after taking the tank off

GZ Jess

06-05-2010, 11:16 AM

Easy Rider

06-05-2010, 11:21 AM

Is it correct that in order to check the plug I will need to remove the gas tank. I am reading the service manual and that is all I can find related to the plugs.

Previous post covers that BUT.......it is highly unlikely that the plug has anything to do with your present starting and fast idle problem. At this point, I think it will be a fair amount of effort expended for no good reason.

When the choke is ON it is closed; when OFF, it is open.....but that's technically not true of modern carbs......so it is really best to use ON and OFF to avoid confusion.

I am pretty sure that one of your first posts stated that you were pushing the lever the wrong way to activate the choke....ie turn it ON. (I could be wrong though.)

[edit] You said: "It will only start if the choke is closed (pushed all the way forward)"
That would mean that you are putting the choke OFF. While some bikes will start with no choke, most won't......and you don't get the benefit of the fast-idle effect that goes along with a partially operated choke either.

Easy Rider

06-05-2010, 11:28 AM

Okay thanks for the tank/plug reply. I now have removed the air filter and can not for the life of me figure out how to look inside. One end has the "cup" thing on it and the other is just flat and glued to it! Thanks again!

Yea, that's a little tricky. The cup thingy will pop off if you pry with a screwdriver or similar.....and it should then snap back on.....but it really isn't an important part; if it doesn't go back on it's no biggie.

The important part is that it is in place, has no holes in it and doesn't appear to be saturated with gas or oil.........or have a TON of dirt inside.

While you are in that vacinity, inspect the rubber boots from air box to carb and from carb to engine. I found mine so loose that I could grasp the carb and turn it without much effort at all.
Also look INTO the air box and inspect for cracks, holes, etc.

This would also be a good time to uncap the airbox drain hose and drain it out; what comes out might be an ugly mess of oil and water. Have something ready to catch it. The cap MUST go back on; it won't run right without it.

GZ250

06-05-2010, 02:24 PM

FOR GZ250:

Spark plug: to change or inspect the spark plug you do not need to remove the gas tank. above the spark plug there is a metal piece that has to be removed to expose the plug.

Choke: while sitting on the bike if you pull the choke lever towards you it is ON, choke activated, if you push back it is OFF. when the trouble started with my choke it seemed to be working (the level part only) going back and forth but the cable inside actually was not moving much. i experienced a lot of gas smell in my air filter and the local guy atthe dealership told me to replace the cable. oiling did not work in my case.

nothing is absolute. you can have a very old plug, air filter or anything else and your bike still be working perfect. But when some trouble stars always start with the easy and DIY stuff.

alantf

06-05-2010, 02:46 PM

FOR GZ250:

to change or inspect the spark plug you do not need to remove the gas tank.

:plus1:

blaine

06-05-2010, 03:28 PM

blaine

06-05-2010, 03:35 PM

Is it correct that in order to check the plug I will need to remove the gas tank. I am reading the service manual and that is all I can find related to the plugs.

You only need to remove the left side chrome cover to gain access to the spark plug. :2tup:

patrick_777

06-05-2010, 03:45 PM

Look in the How-To forum for changing the sparkplug.

Water Warrior 2

06-06-2010, 03:24 AM

Also, you'll need a 14mm socket to get the plug out if i remember correctly - i'm only mentioning this because the first time i only had a small socket-wrench kit that went up to 12mm so i could change the plug even after taking the tank off

N.G.K. sparkplug takes a 18mm socket.
That would be an 18mm spark plug socket or 18mm deep socket. Should be almost identical in dimensions as a roll or quarters. And yes I checked.

GZ Jess

06-06-2010, 10:12 AM

I checked the air filter yesterday and it had no odor and was not dirty at all. I filled the tank with gas and Berryman B12 Chemtool (per bottle) and let it run in the garage for a short time (ride was canceled due to rain). I was able to get it started by holding the throttle open slightly and not turning the idle screw. I did play with the choke (after reading the owner's manual I have it right but may have typed it backwards) and upon moving it forward I get a momentary fast idle but then it goes chug chug and wants to stall out unless I give it gas this is at half or all the way forward.

So anyway, I am going to actually ride today and see if the Berryman's helps at all but I think I will also investigate the choke cable when I have more time. Thank you everyone for your help.

GZ250

06-06-2010, 11:22 AM

and let it run in the garage for a short time (ride was canceled due to rain.

Knowing everything yet people do forget. Never run an engine in a garage or if you have to do it open the doors and have proper ventilation. Unconsciousness can take over without you realizing it.

Easy Rider

06-06-2010, 12:27 PM

I did play with the choke (after reading the owner's manual I have it right but may have typed it backwards) and upon moving it forward I get a momentary fast idle but then it goes chug chug and wants to stall out unless I give it gas this is at half or all the way forward.

We are making progress......I think. :)

What you describe above indicates that you are moving the choke toward OFF too soon; the engine needs to warm up more before you turn the choke completely off. It is perfectly OK to ride with the choke partly ON......for a little while.

Given the history, your idle stop screw could be too low now too. You can set that properly once you ride it far enough to get it completely hot.....and with the choke completely OFF.

Once things are working properly, you should be able to have it fire up pretty quickly with about half choke, or a little more, and without touching the throttle at all until you hear it fire.

Then you can reduce the choke a TINY bit at a time, just to maintain a slightly fast idle speed but not racing too fast........until, after a few minutes or a few miles, you end up with the choke completely off.

GZ Jess

06-06-2010, 12:56 PM

GZ Jess

06-06-2010, 01:08 PM

Easy, I do understand (I think) the operation of the choke and about easing it closed a little at a time. My question now is, on my hubby's bike if I (his choke pulls to come on) pull his choke I can immediately tell a difference in the revs and the smell of the exhaust and pushing back in makes a big difference if it warm. On my bike when I open the choke I can tell a difference in the smell of the exhaust but say I pull it forward 1/2 way and stop, I get a momentary fast idle but then it goes back down to where it was before I opened the choke. Same if I open it all the way, momentary fast idle but then resumes idle as if choke were closed. Shouldn't it stay at a fast idle (when warm) as long as the choke is open and resume the normal idle when closed?

I really hope I am explaining this well enough and if you ever get to Ohio, I owe you a beer or maybe pop, your choice, or two for the frustration!

fairweatherrider

06-06-2010, 02:19 PM

I had somewhat similar problems and this forum definitely helped me out. I changed the spark plug ( removal of tank not necessary). I used the standard plug, NGK DR8EA and checked the gap before installing. Maybe you need a hotter plug. Don't know. I removed the air cleaner (blew air ONLY from the outside of the filter and not the inside) and then prayed gumout carb and choke cleaner in the intake while it was running. Keep the throttle a little fast or it will stall. I adjusted the cables per the manual for throttle grip gap as specified. I adjusted the idle screw and it seems to be running well.

blaine

06-06-2010, 02:56 PM

Easy Rider

06-06-2010, 03:42 PM

Shouldn't it stay at a fast idle (when warm) as long as the choke is open and resume the normal idle when closed?

Yes, I think you have that all figured out right. I think.

Is it possible that what you are observing is happening JUST because the choke lever/cable mechanism is loose and isn't staying where you PUT it ?? That does happen sometimes.
If that's the case, I'm not sure how you would "fix" it on a GZ.

I think it would help with future discussions of the problem if you could change your wording to: choke ON or choke OFF.....instead of open and closed; actually I think it would help a LOT. :tup:

PS...not sure where in Ohio you are but I try to get to the dirt track races at Eldora Speedway - Rossburg,OH occasionally.....but I suspect that's still a fair ways away from you.

5th_bike

06-09-2010, 01:05 AM

I used the standard plug, NGK DR8EA and checked the gap before installing.

You know how to check the gap don't you, when your nail just fits, it's good to go.

Water Warrior 2

06-09-2010, 01:44 AM

I do hope you are joking.

blaine

06-09-2010, 02:06 AM

I do hope you are joking.

Spark plug gap is 0.6mm to 0.7mm.

patrick_777

06-09-2010, 02:29 AM

You know how to check the gap don't you, when your nail just fits, it's good to go.

Most ridiculous thing I've seen posted on this board in a LONG time. God, I hope you're joking.

Water Warrior 2

06-09-2010, 02:08 PM

Anyone know or care about the thickness of 3 coats of nail polish ?? On the other hand I have been told that a penny match book cover is 18/1000ths of an inch thick. Doubled over it is 36/1000ths and a cheap easy way to be close on a plug.
That was told to me by an old backyard mechanic who set his chevy ignition points that way at 18/1000ths.

5th_bike

06-09-2010, 09:10 PM

Most ridiculous thing I've seen posted on this board in a LONG time. God, I hope you're joking.
Thank you for your appreciation. :)
This was taught to me when I was about 13, toying around with mopeds. Actually, you should use your thumbnail.
I recently checked after I set my spark plug to 0.6 mm - my thumbnail still fits exactly.

So, was I kidding - kind of, but also kind of not.
Do I use a feeler gauge to set the spark plug gap - yes.

FYI the average male nail is 0.6 mm and the average female nail is 0.5 mm. A little nail polish should help there (thanks WW).
Nails also get thicker with age, so you can't use this shortcut forever...

The point being, did you realize you are carrying your own set of feeler gauges around ? :2tup:

fairweatherrider

06-09-2010, 09:45 PM

Now THAT'S Funnnny

Viirin

06-10-2010, 08:48 AM

damn 18mm? i was way off - sorry

GZ Jess

06-10-2010, 10:42 AM

I have yet to get to checking the plug but I have stopped using the idle screw to start the bike and have run about a whole tank with the Berryman's in it. Now I "turn on the choke" and start it but have to keep the throttle on a little for a few minutes and then turn the choke off. After that it will stay running, but the engine will occasionally still race after it is run hard or a quick stop. I wish our bikes had the throttle lock! The popping (or what I called backfiring) has decreased and it rarely ever does it Yay! So I think I am making progress.

Jessica

bonehead

06-10-2010, 12:09 PM

Easy Rider

06-10-2010, 12:23 PM

Jessica, sounds to me like you may need your valves adjusted on the bike. Don't know the service history, but mine was doing exactly what you are describing and I adj. the valves and it fixed the problem.

WOW......good information.
I think she is indeed making progress.

It sounds to me like the throttle cables might be sticking now.......or there is a vacume leak.
It also sounds like things are working well enough that the idle screw could be tweeked up just a bit now.

Does moving the choke lever change the idle speed......while it is warming up ??
If it does NOT, then there is still a probem with something in the carb.

I feel a need to repeat that the choke is not an all or nothing device. Once the bike starts, you should be able to reduce it in small steps to maintain a proper idle speed until you finally have it all the way off. If your idle speed is not coming up enough to keep it running then, of course, that doesn't apply......and there is still something amiss.

At some point, you may have to consider taking it to a shop. Manually cleaning the carb should take about 2 hours of shop labor, which would cost about $150 in my area. Maybe they would find something easier and cheaper instead.

GZ Jess

06-11-2010, 11:30 AM

Well I finally got to the plug, not a bad job at all. When I started to work at getting the wire off (black cap thing) I noticed that the plug was so loose it wiggled in the block. I got it completely out using my fingers only. As you can see by the attached pic the plug is not discolored or overly corroded. I don't have a gapper so I am just going to put it back in and tighten it correctly. I will go for a short ride, hopefully a tag, and see if anything has changed. I think I will pick up a new plug and gapper when my new air filter comes in (had to order) and replace it soon after. Thanks everyone and I will report back shortly!

http://s3.postimage.org/C0Wlr.jpg (http://www.postimage.org/image.php?v=PqC0Wlr)

Jessica

Easy Rider

06-11-2010, 11:35 AM

I noticed that the plug was so loose it wiggled in the block.

WOW. You're lucky that the threads weren't damaged. That could cause it to run funny.
Just guessing, the gap looks a little wide on the old plug; it looks a little dark too. Good call on getting a new one.

GZ Jess

06-11-2010, 01:18 PM

Now I have reinstalled the old plug (for now) and tightened it just past finger tight, I don't have a torque wrench yet. It started up with the choke on and only required me to hold the throttle for about half the time as before. It ran for a little while (maybe 3-5 min) in the garage and I was able to start to turn off the choke but not all the way. Later I will go for a ride and evaluate further but tightening the plug seems to have helped the starting a little and I can't wait to see if it has fixed the racing idle when I stop and it is hot. I am still going to get a new plug, check the gap and install when I can get one. Thanks.

alantf

06-11-2010, 03:36 PM

Now I have reinstalled the old plug (for now) and tightened it just past finger tight, I don't have a torque wrench yet

I might get shot down in flames for this, but here goes - In all the years I've been riding/driving, I've NEVER used a torque wrench on the plugs. In fact, the plug spanner supplied with the GZ, could in no way be described as a torque wrench. After the plug is finger tight, it just needs the plug spanner to snug up the plug, & squash the soft washer to make a good, tight, seal. I'm not trying to be derogatory, but I doubt that you (o.k., any normal woman :blush: ) could tighten it enough to make it "too tight" with the bar supplied (screwdriver blade!) :2tup:

GZ Jess

06-11-2010, 03:44 PM

Alan, I do believe you are right about tightening it. I was just cussing earlier in the garage about not having enough strength in my hands to do the mechanics. I have always liked working the the garage and trying to do anything a man could do. But I am not as strong, so I do agree with you.

However, I may be a dolt but I could not figure out how to finagle that tool in to the plug. The bar that the cover bolted to was just in the way! Oh well it is back together now.

Jessica

Sarris

06-11-2010, 10:42 PM

Most folks don't use a torque wrench for spark plugs.

I use the old rule of tighten 1/4 turn past finger tight for a new plug (a little less for an old one). A loose and/or bad plug will cause all sort of running issues, so get that new plug and tighten it per my instruction and you'll be just fine.

Then take it out and run the crap out of it for a few miles and blow the crud out of it. You'll be surprised how much better it will run.

:2tup:

GZ Jess

06-15-2010, 11:31 AM

The only reason I mentioned the torque wrench what because of the how to section. But if I don't have to worry about it even better!

I just wanted to say that my bike is now running like a dream, starting it still takes holding the throttle but not near as long as I used to. Tightening the plug did it! Thank you everyone!