Tick tick clunk!

[Goose51683]

I've read many of the ticking posts of here and unfortunately none of them go to the extent my bike is at.

I had the ticking and a quick search led me to believe the issue was the valves, which was not an immediate concern, or wrong type of gas, and again not an overly immediate issue. So for the rest of the week I drove the bike to work as it is my only transportation at the moment. Well, tonight I had planned on changing the filter and the oil but after about 30 mins of riding how I heard what I guess is best described as a pop, or more like what you hear on the movies when a grenade is thrown down a foxhole. Anyways, the bike dies and I end up on the side of the road. The first attempt to restart actually had the motor turning, not firing but at least turning. The second attempt and all subsequent starts came up with nothing but a clunk. Not a click, but a solid metallic clunk.

Where do I even start. I noticed that the oil was very low. I know I checked the oil level not a week ago. So A, where did the oil go and B, am I totally boned and the engine is locked up.

My plan was to remove the starter and see if anything would turn by hand. If not i will start disassembling the entire motor and going from there I guess.

Anyone have any advice at this point?

[ovilc88]

I don't want to jump the gun here, but that sounds like a piston hitting the spark plug. Pull the plug out and examine it. Start there.

[jonathan180iq]

Ditto. Pull the plug and see what you see.

[Goose51683]

Thanks guys. What should I be looking for?

[jonathan180iq]

Any kind of damage at all. If there are metal flakes or indentions or anything along those lines. With a scope light, you should me able to eyeball if there is damage in there too.

It's weird that all of this stuff is happening to people recently. We've gone years here without any serious mechanical failures. I guess when it rains it pours.

[Goose51683]

Not the best pics but I forgot to bring a boroscope home from work. Let me know what you guys think. I have the tank seat and carb removed so if I need to dig deeper now is the time I guess.

[Goose51683]

I did want to ask since it looks possible, why does it mean if the piston is hitting the plug?

[jonathan180iq]

...... Sorry dude. It's time for a tear down. :(

Has your oil level suddenly dropped as well?

[Goose51683]

yes it has...

So if I tear it down, am I just looking for all the damage I can find, then replacing damaged parts, gaskets and seals?

If so does anyone know of a good tear down thread on here. I have tried searching but I haven't found anything yet.

This will be my first tear down and I need to do it efficiently as my wife is already on my backside about when she will have her car back. lol

[Goose51683]

Just looking up engines but would a "81 19981 SUZUKI GS250 GS 250 T ENGINE MOTOR #5069" fit a 2008?

Just planning for the worst

[Goose51683]

Another quick question- Is there anyway to loosen the tension enough to take the chain off without removing the back wheel?

[blaine]

Another quick question- Is there anyway to loosen the tension enough to take the chain off without removing the back wheel?

Just loosen the adjusters & the wheel will slide ahead enough for the chain to come off.(rear wheel needs to be off the ground.)
:) :cool:

[Goose51683]

Thanks Blaine!

[Goose51683]

So I have engine apart and it is quite obvious one of the valves broke of and it currently firmly embedded in the piston head. It also seems that the area surrounding the valves is pretty banged up. Is there a piece that can be replaced there or do I need and entirely new valve assembly. Also what looks like the piston sleeve looks to have a very minor scrape on the side. Does this always need to be replaced, if so is it possible to just replace the sleeve?

One last thing. Does anyone know where to find these parts other than eBay?

[Goose51683]

Here are the pics

[Goose51683]

Does anyone know if GZ250 parts and GN250 parts are compatible with each other?

[blaine]

Does anyone know if GZ250 parts and GN250 parts are compatible with each other?
Yep should be the same. :) :cool:

[Goose51683]

Thanks Blaine. I was able to find everything on a GN250 I needed for around 350 compared to the 750 just for the cylinder head of a gz250

[jonathan180iq]

Geeze man!

...That's gorgeous! hahaha. You should keep the grenaded piston just to look at.
It seems very strange to me that we have had so many of these pop up lately. I'm not really sure what's going on in the world of the GZ. Strange happening indeed.

You should be able to just smooth out the cylinder wall with one of those awesome ball-scrubby-polisher things. And you MIGHT be able to clean up the valve surface with lapping and a professional job, but I would honestly just look into getting a new head. I think this part is separate on Ronayers but I don't remember. I had looked it up for someone once before.

I hope it works out for you man

[Goose51683]

PARTS ARRIVE TODAY!!!!

To bad I'm in Texas, but as soon as I get home tomorrow it's time to rebuild me an engine and finally get back on the road. Any wishes, prayers or just general good thoughts would be greatly appreciated.

[Goose51683]

Everything is installed, bike is bak together as per te service manual. I'm getting spark. I can smell gas getting to the cylinder, the starter turns over and I can visually see the piston movin in the cylinder. But no turn over. I'm not even hearing it try. I have never checked compression so I'm gonna search that topic next. My fear is the issue is timing even though I went by te book and checked several times to ensure the t mark was lined up with the cam. Is it possible or that to be 180 off or something. Is there any other way to check timing?

Also, I'm not getting a neutral light. I've checked my wiring, everything is still
Connected. I used to be able to have the bike in neutral with the stand down and get it to kick over but I can't do that now. I don't know why that would keep me from tuning over now though.

Any help from anyone would be much appreciated.

[alantf]

Is it possible or that to be 180 off or something.

I'm no mechanic, but I've heard that this is certainly possible. Apparently, the way to tell, is to pop something such as a drinking straw into the plug hole, to tell when the piston is up.

[blaine]

Is it possible or that to be 180 off or something.

I'm no mechanic, but I've heard that this is certainly possible. Apparently, the way to tell, is to pop something such as a drinking straw into the plug hole, to tell when the piston is up.
Yes That will work.Just make sure your on the compression stroke (valves closed) & should be able to fill pressure blowing out of plug hole.If off 180 degrees valves will be open when piston is up (exhaust stroke)
:) :cool:

[jonathan180iq]

I agree it feeling like a timing issue. Your compression will be way down because your timing is off so much...hence, no start.

[Goose51683]

Thanks everyone. 3 responses per night is awesome. Ill check this as soon as I get off work and let you all know how it goes.

[Goose51683]

Okay.....I checked the timing. It was exactly as the manual says it should be.
I inspected the valves operating correctly. They appeared to check out.
I checked the carb, both are clean and intact.
When I opened it there was ample fuel inside soon know everything to the tank is fine
I checked out all of the fuses. They were fine.
I didn't do the dollar test yet as the battery died on me. Charging it now.

If anyone has any other ideas at all I would be very interested in hearing them.

I'm just about out of my own ideas. This is a very simple machine and I'm getting a bit frustrated not being able to figure this out.

Thanks

[Goose51683]

Okay I admittedly don't know much about engines but I was thinking. How does the spark plug sync with the engine. Is it possible that I have the timing right in te motor but not between the motor and the plug?

[isaac]

If it's not backfiring out of the intake and exhaust, you're not 180 degrees off with cam timing compared to ignition.

This is simple stuff, probably solved by either

A) You need a new spark plug. Fuel fouling will not show up in a traditional spark test. The plug will fire normally outside the cylinder. Inside the high pressure cylinder it won't fire right. This sometimes can be fixed by just taking a torch to the plug (though sometimes it's too messed up). If you heat it with a torch, install it right away and then crank it's much more likely to fire, but not guaranteed.

B) The carb got installed wrong. This can manifest itself in all sorts of ways, but mostly it'll be at start and idle. The extremely easy way to check this is to first put a new plug in there, then spray starting fluid (or carb cleaner, or brake cleaner, or hold a gas soaked rag over the intake) and crank it. If it fires, then the carb is your problem.

C) There's something else causing over/under fueling. Either you forgot to hook up the vacuum hose between the carb and the fuel valve on the tank, the carb isn't sealed to the engine, or the carb gummed up while it was sitting or the fuel valve in the carb is stuck. Small engines have small carb jets and gum up extremely easily. Again this is something easily ruled out by spraying carb spray and cranking.

D) The cam is off by a tooth one way or the other. But you'd probably get at least a kick while cranking. If it's off by more than a tooth or two it'll probably bend valves.

E) Gas-washed cylinder walls. Metal in cylinder walls absorbs oil. That micrometer-thick slick of oil helps with compression. If you had too much fuel going through the engine, especially after it had sat for a long time, the cylinder walls can get gas-washed and the engine will have less compression than normal. This can be rectified quickly by squirting some oil into the plug hole, installing a new plug (notice how I keep repeating that), spraying carb fluid into the intake and cranking.

If you check all those and it's still not firing, I wouldn't be shocked if the engine was put back together wrong. But if you really put it back together so wrong that it won't fire but somehow still sounds normal while cranking, compresses audibly every other rotation, and doesn't backfire through the intake or exhaust, then I'd say you're a tooth off somewhere.

The only way you could get the ignition wrong but the cam timing right is if you messed with the ignition pickup inside the right side crankcase cover, which I doubt you did. Did you hook up the ignition coil wiring backward? I don't know if that makes a difference but it may have a one-way transistor in there. What is possible is that you got the ignition right but the cam 180 degrees off. If that happened, as I've said, you'd be backfiring out of the intake and exhaust because the plug would fire just as the exhausts were closing and the intakes opening (during overlap).

I had an undiagnosable no-start on mine once that was cured by a new carb slide of all things. Went from barely running to running perfectly with one part, many months of aggravation later.

[mrgz250]

the ticking sound is possable the cam chain been strestch needs to be replaced send me a e mail Ill walk u through it off idle the tick goes away mine went out & 58k If you do the repair use only suzuki parts u will need more than just a chain to do the repair right email me @ suzukix668@yahoo,com

[alantf]

use only suzuki parts

Do you work for Suzuki? You seem to think that no one else in the world makes parts as good. I agree with waterwarrior. You're starting to p*ss me off, too.

[Goose51683]

First things first. I installed a new plug from the get go, triple checked the spacing on it.

I've checked the carb several times and have reinstalled it multiple times in the past so I don't think it's installed incorrectly. I'll still take it off, shoot some starter fluid in there and see what happens. A the very least that should rule something out.

I've checked the cam and timing chain a few times now. Everything looks to be dead on. Even if it wasa tooth off I would expect some firing, it would be off but it should still at least attempt to fire.

Also the cam chain is tight so I don't think it's stretched. Turning the engine a few times from the generator side the timing mark consistently line up so I don't think I'm losing anything there.

I guessi will shoot a little oil in the cylinder and see if that lubes things up at all. Ill also saok the car in gasoline for awhile and see if that loosens anything up.

Really at this point I'm out of ideas.

[Goose51683]

Latest update.

I shot some starter fluid into the cylinder and tried to start her up. Not much happened other than a "plumb plumb plumb" sound. No firing.

I also added some oil into the spark plug hole and rolled the cylinder through a few cycles. It seemed to move easier but after trying to start it there was no real improvement.

I keep coming back to timing. I aligned the t mark and the cam exactly as the manual says. Can anyone verify this is correct for a 2008. I know there are not supposed to be any differences but I just want to confirm that.

Otherwise does anyone have any more details on the electrical side of the timing between engine and spark plug. I a entirely unfamiliar with this so please use small words. Haha

[Goose51683]

Looking through the manual (again). I noticed there is supposed to be a spring behind the neutral switch. I do not remember ever seeing a spring here. It's possible there was but I lost it or that it was never here. What's the chances of this causing at least part of my issue?

Anyone know the springs purpose?

[raul10141964]

If the key on the Rotor Assy (part #5) is missing o damage the ignition timing will be off

http://s23.postimg.org/d6a0h2ec7/gz_parts_manual_20.jpg (http://postimg.org/image/d6a0h2ec7/)

[Goose51683]

Raul,

When you say part #5 what are you referring to?

Is it from a diagram in the manual?

[raul10141964]

part # 5 on the picture

[Goose51683]

I'm sorry. Te picture didn't pop up in my phone hence my confusion.

[Goose51683]

Part 5 is not the part I'm referring to. I'll try and find a diagram to explain what I'm talking about.

[Goose51683]

In the service manual, page 3-58 it references a spring and a terminal that are installed prior to the neutral switch. I do not appear to have these parts on my bike but am also having trouble finding them in the parts manual.

[Goose51683]

Okay I have determined that I am missing the spring for this. I found the contact and will be looking for a spring that fits today. My question is, does anyone know if the neutral switch will do anything other than turn on the neutral light? With this missing will it actually affect the bike from running?

[Goose51683]

Okay spring is replaced and still nothing. I am seriously about to lose my mind. About to push this thing to the local quarry and say good riddance!

[raul10141964]

do not trust MRGZ250 he is spanning all the treads

[Water Warrior 2]

Okay spring is replaced and still nothing. I am seriously about to lose my mind. About to push this thing to the local quarry and say good riddance!
Check the neutral light bulb itself or just replace it with a new one. Determine if it will light up when shifting through the gears. If it lights up in a gear rather than neutral you have something out of adjustment. This is all I can suggest and don't know enough about any adjustments but it may help you sort out the bike. It is likely something simple that just needs to be tracked down.

[Goose51683]

I reworked the neutral sensor. I had the spring and the contact in the wrong hole (thats what she said HAHA)

Anyways the neutral light now works correctly and and at the right times however I am still not getting any firing while starting up. The process is getting pretty slow due to the fact that I'm wearing my battery down pretty quick with all of these attempts to turn her over.

I'm gonna run through the electrical system tonight. I have a feeling I have a bad ignitor that is giving a spark at the wrong time. Not entirely sure how to test this yet but I'll work on that tonight.

If anyone has tested the ignition circuit before I'd really appreciate any insight you may have.

[jonathan180iq]

Have you performed a compression test yet? Just to kill that variable? I think you can borrow a tester from O'Reilly or Autozone.

[Goose51683]

I borrowed a tester from autozone but the connections were all much bigger than the hole for my spark plug. I tried holding the hose to the hole but I wasn't able to get any reading. Sitting the spark plug loosely in the hole and cranking the engine with a wrench it is easy to see I'm getting some compression but I have no idea of a number. I was thinking about borrowing a timing light tonight to verify that I'm getting a spark around the T mark on the generator.

[Water Warrior 2]

If the battery is getting low on power that will affect your attempts to start the bike. You might want to beg, borrow or buy a trickle charger to top up the battery. The starter and ignition need a full battery to share.

[Goose51683]

I've been charging it over night every night. I just ran through some resistance checks of different components of the electrical system. I found that the ignitor, the 3 x 3 black box that has an 8 pin plug, had several inconsistencies with the chart in my manual.

I need an idiot check before I buy one though. Would a bad ignitor through off my spark timing (which is what I think is happening)? I checked the ignition coil and I got the correct resistance, same with the starter relay (plus I know the starter works when I try to start).

I havent checked prices or availabilty yet, If I have to order from china again and wait another week I think I'll lose it, not to mention my wife will lose it on me and not in a good way.

[Goose51683]

Holy *@&%!!!! That ignitor is going for over $200....or double that for the brand new Suzuki brand part.

How can that piece be 1/10th of what I paid for the entire bike?

[Water Warrior 2]

Be sure you need one before biting the bullet. Check on E-bay too. Also check here for parts for sale. A member may have one gathering dust.

[Goose51683]

Well I checked the resistance from terminal to terminal against the chart in my manual and I found several incorrect readings, do you know any other way I could check this before I make my wallet cry?

[Water Warrior 2]

Well I checked the resistance from terminal to terminal against the chart in my manual and I found several incorrect readings, do you know any other way I could check this before I make my wallet cry?
Alantf is very good at electrics and trouble shooting. He should be able to help when he shows up. A couple other members are good too(no offence guys)but I always think of Alantf first.

[Goose51683]

Well I can't wait to hear from him. I'm a decent troubleshooter but this is all new to me.

[jonathan180iq]

Send him a PM. He's the best electrician we have.

[alantf]

I found that the ignitor, the 3 x 3 black box that has an 8 pin plug, had several inconsistencies with the chart in my manual.



If you're not getting the readings that the manual says you should get, then it would appear that there is a problem with this component.

[Goose51683]

That's what I figured but I thought I'd ask the group first before I threw down a chunk of money.

Thanks guys. Ill order the part tonight and let you know what happens.

[Goose51683]

Ugh 400 for the part and about a week lead time. Almost makes me wanna cry.

[Water Warrior 2]

I would scout Ebay first.

[Goose51683]

Too Late, I bit the bullet and ordered one from a father and son shop near me.

I haven't had the most success with Ebay.

[isaac]

Well good luck getting it all back together with the new part but I can pretty much guarantee that it will be something you did during the teardown and rebuild that's causing this, assuming it wasn't the catastrophic damage itself that did something you can't see. The simplest explanation is usually right in these situations, and this is coming from a guy who's blown engines like a hobby for the last decade.

You really need to make a concerted effort to retrace your steps.

BTW If you're getting crank and spark then clearly none of the safety switches are an issue.

If the spark is orange instead of blue, you've got a weak ignition part (unless the battery's weak), but it's not like you had an ignition part magically fail at the exact same time you had catastrophic internal engine damage. That kind of coincidence just doesn't happen unless the crankshaft wobbled so badly that it broke the ignition pickup in some way when piston met valves.

[Goose51683]

Thanks Isaac. The part is already ordered and no. Refundable so I might as well try it at this point. It tested bad with a meter so there is some issue with it at this point.

[Goose51683]

AHHHH!!!! 2 weeks and still no parts!!!!

I'm just hoping to get back on the road before it snows!

[Water Warrior 2]

Just had a thought pop up in my old skull. Alantf can likely varify this because I have no real talent with electronics. Does the igniter box have to be properly grounded to function properly?????

[alantf]

[attachment=0:3cb2s68p]img082.jpg[/attachment:3cb2s68p]

Sure looks like it. You can see the B/W (black & white) ground cable at the bottom of the diagram. :)

[Water Warrior 2]

Thank you Alantf. I knew you'd be along shortly.

[Goose51683]

Thanks for the thoughts guys, unfortunately I verified my grounds first thing.

I guess since I have plenty of time I can double check though right.

[Goose51683]

Just got word on my part. Apparently it is back ordered and Suzuki decided not to tell the bike shop I ordered it from. So best case scenario, I have it the end of next week.

Worst case a black hole opens up and swallows me as soon as I submit this.

Maybe I have those switched.

[Goose51683]

I'll be looking into the ground you mentioned tonight. Any chance you know which pin coming off of the ignitor is the ground pin.

On a side note it looks like I left the battery on the charger when the power went out and then forgot to reset the charger....so now my battery is dead as a doorknob.

I've lost count but if I have to pick up another one it'll make 4 batteries in less than 6 months.

This cheap little bike is costing me an #$%*@ ton. Goodness help me if my wife ever starts doing the math.

[alantf]

Any chance you know which pin coming off of the ignitor is the ground pin.

All grounds are black/white cable, so look for a black/white behind the pin.

[Goose51683]

Checked out grounds last night. Highest resistance is .3-.4 ohms. That's inline with what id expect.

[alantf]

Yes, that's probably just the resistance of the leads.

[Goose51683]

Yeah. Anything under an ohm wouldn't really concern me. But that does rule out another thing. I guess I'll wait for the ignitor to show up. If that doesn't fix the problem then I will really be at a loss.

[Goose51683]

Pardon me while I vent....


"%*#^{+<+#*\#_=€{^#]#"

This piece of €}*# is still not working!

Just got the new ignitor, tried to few
It up, nothing. I am seriously about to scrap this f!#*€@r.

Ahhhh!!!!!

[twelveport]

Does anybody make a long block for a swap?

[isaac]

You should seriously make an attempt to ascertain compression. The quick and dirty way is to stick your thumb over the plug hole with the throttle open and a good battery to crank it. The compression should seriously be blasting your thumb off that hole. If it's not very difficult to hold your thumb to the hole, then you're low on compression.

Just be sure your battery is good otherwise the reading will be way off.

[Goose51683]

I seem to be getting a lot of gas collecting in the carb so I decided to tear the carb apart and clean it out. It's soaking right now.

I'll put it back together tonight hopefully and try checking the compression. I have checked this way before and was getting compression at that time.

[jonathan180iq]

What is the carb doing? Is it literally overflowing gas?

[Goose51683]

It is not but when I take the carb apart there is an awful lot fuel in the carb but I don't seem to get much of a smell in the piston. It would explain not getting any ignition.

Plus I can't stand not doing something so it's just another portion of my bike ill take a deeper look into. I had to get lucky eventually.

[Goose51683]

Alright here is the latest and greatest.

I've managed to reel in my frustration and try to get productive again. I disassembled the carb, soaked it in gas for a day, cleaned and checked all the ports, everything appears to be free and clear. Reinstalled, still nothing.

Went through and checked fuses again, everything checks out. Pulled the starter plunger on the carb, verified it it working.

Charging the battery again as we speak.

Pulled the side stand relay for shits and giggles, it checks out.

Toggled the kill switch multiple time, don't think that has anything to do with it but at this point what do I know.

Didn't have the daylight to check compression at the piston but I am getting puffing out of the exhaust.

I'll check my spark again tomorrow to ensure I still have that.

I hate to say it but my next step may be a total tear down of the electrical system. I guess I wanted to do a require anyways, I was hoping to ride out the summer and wait till winter but as things seem I may not have that option.

I am going to try and find a 12 volt power source that I can use to test the starter relay but since my starter is working that wouldn't make much sense (....sorry, thinking out loud)

Any suggestions at this point would be really really helpful.

Thanks guys (and gals)

[jonathan180iq]

I think you're jumping ahead of yourself...

Fuel - Spark - Air(compression)

Do you have these?

Before you do anything else, check for spark on pressing the starter. If you have spark, then the electrical system is good enough for now.
Test compression - even with shit compression it should puff n' pop. (AFter that would be timing... you did just rebuild this thing with non standard parts also, so there could be a number of things here.)
Shoot some starter fluid in the chamber and see if she'll even try to purr. If your carb isn't doing it's job, then this will show you that.

[Goose51683]

I will start over from scratch but so far in recent past I have:

checked spark at the plug
checked compression, have not used a compression checker though.
shot starter fluid in the chamber with no results.

I just got a timing light today to check that.

Would I be safe to assume that if I shoot the light down the hole on the gen side I should get a light when the T mark shows through the hole on the cover?

[jonathan180iq]

When set right, that's what they'll do. They blaze up and if everything is right, the two arrows will illuminate very close to each other.

I don't know what compression is supposed to be on these engines, but you should be able to pull that from the service manual. Plus, considering you just did a rebuild, they should be just about factory.

[Goose51683]

well the issue is I'm having trouble finding a compression tester that will fit this bike.

[Goose51683]

Okay, took the time to go back through everything again last night.

I have a good spark, I am reasonably sure I am getting fuel to the cylinder BUT...

When placing my finger over the hole for the cylinder and trying to fire the engine I do not get much of a pushback. I feel the slight pop but nothing close to "blowing my thumb off the hole" like has been described.

So of course the part of the bike I am weakest on, compression, seems to be the next possible issue. Can anyone school me up on compression. I know as the cylinder rises it should cause the air to compress in the cylinder. In order for this to occur you have a have a good seal around the piston rings and the valves need to seat properly.

My question now is do i have to pull the engine apart or is there anything else I can check prior to that.

[jonathan180iq]

Did you do this finger test by hand cranking the motor or by thumbing the starter and letting it physically pump it over and over? Did you let it spin more than a couple of times? You shouldn't have been able to hold your thumb in place...

Assuming your piston and rings were the proper size and that they seated properly, you still need to look at the timing. If, for example, on ever compression stroke, one of the valves is open, then all of potential "boom" is being lost through that leak. It's possible that it's so off that your valves are closing on the suction stroke and you're never making compression at all, really. Timing is a big deal if it's really off. This is why burned valves cause motors to not run... or valve seats that aren't seated, which is what you replaced, right?

Check your timing with the light. If the marks hit properly and your vales are within spec on the measurements, then the problem, I would think, would be in the seats and the valves themselves.

Hit up Ovcil88. He recently replaced his piston, as have a couple of other members here recently, and they have some more first hand insight into something that maybe you missed?

[Goose51683]

I thumbed the starter. when I installed the valves I checked to make sure that the valves seated securely. It was very easy to keep my finger over the hole. Looks like I'll check the valves next to see if they are actually seated.

Do you know at what point the exhaust valves and in the intake valves open and close? If I check through the upstroke I would imagine that all the valves should be closed correct?

Is this kind of info in the manual? I don't recall seeing it but I may have overlooked it.

[jonathan180iq]

Poor man's method is this:

Pop the valve inspection covers. When the intake lobe is at 6 o'clock (completely engaging the valve), your piston should be at the the very bottom of the cylinder. There is the compression stroke to follow, where both valves should close. When both valves are completely disengaged, your piston should be at TDC. Test this with a light and a pencil.... (Easy on the pencil. People have talked about dropping an eraser in the chamber... Just don't use a shit pencil. Get a fresh one that fall won't apart when you touch it.)

You'll have to do this by turning the motor over by hand so you can see what's happening. Get a little flashlight and have a buddy help you out. This will at least tell you if you are in the general zone of if you're off by a whole rotation or something...Plus, this is free and will only take a few minutes. If your timing is right, then the issue has to be internal.

Once again, if you REALLY need to know, then getting an adapter for a real compression kit is not that hard. I would send you a link right now to one that you can get from JCwhitney, but I think I just gave you enough info to get you there. I would also almost bet you money that you can find one locally so you don't have to wait. (That being said, I just don't think you have enough compression and my gut tells me your whole timing is off but more than just a tooth or something...just a gut feeling though.)

IF your timing is good, then I'm afraid you're going to have to go back in there and do this again.

Just back off mentally for a bit and make sure it's all very step by step. One thing at a time. Don't get distracted and starting working on more than one system at once. One. Thing. At. A. Time.

[JohnC]

First thing I'd do is make sure the valves are actually closing, i.e. check the clearance. Be certain you are on the correct TDC when you do it as there are 2, one where they are both closed and one where they are "rocking" (the exhaust valve is closing at the end of the exhaust stroke and the intake is opening at the start of the intake stroke. If you can see the cam, you can identify the point where the valves rock and a rough check of valve timing can be made by verifying the piston is at tdc. Do not adjust the valves at this point, though. rotate the crank another 360 degrees so both rockers are on what's called the base circle of the cam. Then adjust the valves.

Without going back through the whole thread I can't tell is you removed the piston. If not, you could have a pinched ring causing a loss of compression, too.

[Goose51683]

Whoa whoa whoa....I didn't remove the entire piston etc but let's go back to the two possible scenarios at "TDC". ( please write out what TDC is. I assume its te location of te T mark)

I put the engine at the T mark when I adjusted the valves but didn't pay any attention to the valves actual position, at least not any special attention. Ill add this to the list of things to check.

[alantf]

I'm no mechanic, but from what I've read on this site, the T mark can come up twice in the cycle - both when the piston is at top dead centre and bottom dead centre, so it's possible to get it 180º out.

[blaine]

TDC means Top Dead Center.When the piston is at it's highest point in the cylinder & valves are closed.As stated in a 4 stroke engine the piston goes up & down 4 times for every cycle.Intake(piston going down) Compression(piston coming up) Power(piston going down) Exhaust(piston going up) Hence 4 strokes.Where the "T" is not as important as you think.As long as the both valves are closed, (nose of the cam facing 180 away from the stems)You can go ahead & adjust your valves.No need to worry about the timing marks.Hope this helps.

:) ;)

[Goose51683]

Well ill be damned. That's like a huge freakin part of the puzzle. I haven't had a chance to look at the bike this weekend but this is something I will definitely check. I know I did
Not verify the actual piston position when I set the valves last time. I put it at the t mark and went to work. Thank you so much. I let you all know what I find.

[jonathan180iq]

I do feel like you're off by a whole turn... Like I said, that's just gut. I believe you probably seated the valves and seals just fine.

You're piston is probably on the compression stroke and one of the valves is open - hence no compression. If you just used the "T" mark, without verifying that you were at the right stage in the stroke cycle, then this is almost certainly what happened.

[Goose51683]

At the t mark, verified the piston is at the top
Of the stroke, adjusted the valves. Seems to have more compression but still not firing. Is there any other way to verify the valves are completely seating

[blaine]

At the t mark, verified the piston is at the top
Of the stroke, adjusted the valves. Seems to have more compression but still not firing. Is there any other way to verify the valves are completely seating
Did you verify that the valves were closed by looking to see if the nose of the can was facing 180 degrees away from the valve stem.That way you know that the valves are closed.

;) :)

[JohnC]

When the piston is coming up to TDC (Top Dead Center) on the compression stroke, air should be forced out the plug hole. If you adjusted them incorrectly, thjis may not happen. When the piston comes to TDC on the exhaust stroke, air is forced out the exhaust, but it is harder to detect. The piston must be at the top of the compression stroke when you adjust the valves. If you adjusted them at the top of the exhaust stroke they will not open properly or at the correct time and the engine will not run. If you adjusted them on the incorrect stroke, the clearance will be bigger (huge) on the correct stroke. So, rotate the engine one complete turn so the TDC mark comes up again and check them. If the clearance is too big, readjust them. Then they should be correct.

[jonathan180iq]

So, rotate the engine one complete turn so the TDC mark comes up again and check them. If the clearance is too big, readjust them. Then they should be correct.

:rawk:

[JohnC]

By the way, the easiest way to check them is to get a feeler gauge that is the minimum and another that is the maximum for the valve in question. The min must fit in and the max should not. To be a real pro, get a set of feelers with a (roughly) 30 degree bend on the tip and take it apart. Make up pairs, min and max, and fasten then together with a small nut and screw.

verify that the valves were closed by looking to see if the nose of the can was facing 180 degrees away from the valve stem.

Since there are rockers involved, I think the cam lobe will face away from the rocker cam follower, but I've never actually looked at one...

If you are on the wrong stroke, both valves will (should) be partially open, so if you adjust them here, you need to first adjust out all the "open" then add the clearance, so the valves will then open late, close early, not open very far, and have huge clearance when closed.

[Goose51683]

Thanks everyone.

Last night I adjusted my valves, rolled through till the next time I hit the T mark, adjusted them again, rolled to the T mark and made sure that my adjustments stayed right on. So I am pretty sure that my valves have the proper clearance right now.

Engine is still not firing though. I am borrowing another compression tester today so I can get some numbers from that up here soon.

[JohnC]

I adjusted my valves, rolled through till the next time I hit the T mark, adjusted them again, rolled to the T mark and made sure that my adjustments stayed right on.

I think you are still confused. You should not expect to get the same clearance every 360 degrees, only every 720 degrees. When the piston is at TDC on the compression stroke the valves are closed and should have the published clearance between the tip of the valve stem and the rocker arm. If you rotate the crank 360 degrees the piston will be at TDC at the end of the exhaust stroke. The exhaust valve is closing and the intake valve is opening. The rocker arms are pushing on the valve stems and there will be no clearance. If you adjust them so they have clearance on the wrong stroke then when you rotate the crank to the correct stroke the clearance will be excessive.

[jonathan180iq]

http://www.sphaera.co.uk/images/4-stroke.gif

This photo shows the compression stroke. Both valves are closed and the blue air is being compressed. The very next thing that will happen is the spark plug will fire and it will all go BOOM! driving the piston down. Absolute bottom, the exhaust valve will open. As the piston is driven up, the gasses in the cylinder are expelled through the exhaust. On the next revoltution (after that TDC) the exhaust valve closes are the intake valve opens to draw in more air and fuel. Absolute bottom again, the intake valve closes and the piston, now driving up, compresses the air and fuel just before the big BOOM! (This final part is the TDC that we are concerned with.)

[Goose51683]

Thank you guys. I know it seems simple and it is but with as much as I've been working lately, wrapping my head around this in the few hours I have after work is hard.

[jonathan180iq]

We know. It's not big deal.

Sometimes, having an extra set of eyes on a problem is beneficial... as if having a clearer head to look at something.
And sometimes having 6 pairs of eyes looking at something only confuses you. But I think we're all saying the same thing at this point. Now that you have at all together, you just have to figure out how much compression you're getting (almost none). So you have to figure out why you're not. You changed valves and seats, meaning your messed with the timing of everything, so this is a likely spot to have lost compression due to the system being open on an incorrect stroke.

The good think is that the system is self correcting after 1 part is right. So you only have to get them closed on compression and the others will be there. If there is no compression after that, then we just go from there.

[jonathan180iq]

Ps: In that photo notice the position of the lobes on the valves and the position of the valve heads themselves inside the chamber...

[5th_bike]

Here is a GIF:

[attachment=0:2f74kkyc]4StrokeEngine_Ortho_3D_Small.gif[/attachment:2f74kkyc]

You can easily see that at the end of the exhaust stroke, the valves out/in are still/almost being closed/opened (the cams are still/already touching the stems), but at the top of the compression stroke (where it sparks), both valves are closed and both cams are completely out of the way.

[Water Warrior 2]

Can't remember if this was asked before but here goes. Are you sure the cam shaft is syncronized with the crank? If you got it one tooth out on reassembly the valve timing would be out. You might never get the compression you need. Said my piece so now the rest of the guys can run with it if need be.

[JohnC]

Ps: In that photo notice the position of the lobes on the valves and the position of the valve heads themselves inside the chamber...
The single cam on the 250 does not act directly on the valves. It pushes 2 rocker arms, one intake and one exhaust, up and each rocker arm pushes its 2 valves down.

+1 on Water Warrior's comment. One, ore maybe even 2 teeth out and it might still run, but not well. Any more than that and you risk hitting a valve with the piston and putting yourself back to square one...

[Goose51683]

I've checked the TDC mark against the cam positioning more times than I can count. It appears my valves are closed when I hit that compression TDC mark as well.

I'm checking valve gaps again today but I though I would pull the top and check the timing again for shits and giggle.

Thanks for all the illustrations. Yet again the compression tester I got does not fit the bike so it looks like I have no choice but to order a specialty one to fit the 250.

Being the holiday I won't be spending to much time on this but I'll let all of you know if I do find anything

[Goose51683]

Looking at the cam and lifters. Because the lifters ride on top of the cam I would want my lobes facing off or down at the TDC of the compression stroke right?

So would this be 180 off
http://i41.tinypic.com/2hgwev6.jpg

[alantf]

Why not turn your photos to the correct position before posting them? makes things 100% easier for us.

[Goose51683]

Also, for some reason I can't delete those last post.

Anyways, I'm going to talk this out and see if it makes any sense.

I adjusted my timing 180 degrees from where it was. Currently at TDC on the compression stroke I have both valves closed, however when I pump the motor to check compression I am getting a lot of blowback through the carb. It would make sense that the intake valves are not seated but I've checked the clearances several times.

With checking the loves on the cam I know that the valves are in the correct positions. Is there any thing I'm missing

[jonathan180iq]

Ps: In that photo notice the position of the lobes on the valves and the position of the valve heads themselves inside the chamber...
The single cam on the 250 does not act directly on the valves. It pushes 2 rocker arms, one intake and one exhaust, up and each rocker arm pushes its 2 valves down.

+1 on Water Warrior's comment. One, ore maybe even 2 teeth out and it might still run, but not well. Any more than that and you risk hitting a valve with the piston and putting yourself back to square one...

Certainly. Just making sure he understands what needs to be happening. The gif is much better at doing that, rocker arms aside.

[jonathan180iq]

... however when I pump the motor to check compression I am getting a lot of blowback through the carb...

http://www.manx-haven.com/wp-content/uploads/2012/05/demotivational-posters-well-theres-your-problem.jpg

Which parts that you used were not factory and were not from the Gz, again?
(I'm not being an ass. I seriously don't remember.)

[JohnC]

A little pump back through the carbs at cranking speed is normal. The intake valve doesn't close until a little past the point where the piston starts up on the compression stroke. However, if the photo you posted of the cam is taken with the crankshaft at TDC, then I'd say the cam timing could be off a tooth or two as the two lobes of the cam do not appear to be symmetrical with respect to the valves. It may be OK, but I'd want to make absolutely certain that when the crank is exactly at TDC the cam is exactly where it belongs. I'm also a little puzzled as to why I can see daylight between the chain and the chain wheel. Could it be off a half a tooth? Something just doesn't look right there!

[Goose51683]

the chain is on tight, I may of had the tensioner removed at that point. I did switch the cam 180 degrees after looking at it. I think it was off the entire time. I am getting a substantial puff out of the carb at this point.

My next question is if my cam and my TDC mark are lined up can I be off on my timing. I am still not getting any firing.

Jon to answer your question, the piston head, cylinder, valves, and top of the cylinder (where the valve seats are located) were all replaced

[Goose51683]

Hey everyone, I haven't had much time to work on the bike lately but I did try and turn her over after loosening up my valve clearance a little (i was concerned that I have to little clearance and are therefore opening the valves to quickly)

When I turned it over I stuck my hand behind the carb because I wanted to see if it was sucking or blowing. Fist it is blowing, second it is blowing our gas.

Here's the assumptions I am making from that. I am getting fuel through the carb, and my exhaust valves are not closed at the correct time. Can anyone validate my assumptions.

I know that my valves not being closed could be a timing issue or a valve clearance issue I just want to make sure I am in the right mindset at this point.

Thanks

[JohnC]

An easy, quick way to get a gross check of the valve timing is to put the engine at TDC on the exhaust stroke (not the TDC where you adjust the valves!) Then, rock the engine back and forth a little past TDC and a little before TDC. The two sets of valves should be "rocking", in other words, as you rotate the engine from before TDC towards after TDC, the exhaust valves should be closing and the intakes opening. As you rotate the engine backwards from after TDC to before TDC the intake valves should be closing and the exhaust valves opening. If this is what you observe, the valve timing is close enough to run.

Valve adjustment won't make the difference between running and not running as long as you are close. If they are so tight (no clearance) that the valves don't actually close you will have little to no compression and it won't run, but if you have huge clearances, say .010 instead of .001, it will still run, albeit not that great.

[Goose51683]

Sorry I haven't been around much lately. Work has been killing me lately and I just haven't had a chance to get to my bike lately. Hopefully this week ill have some more time.

[plato1]

I want to thank you all for contributing to this post. My bike has a similar ticking noise issue that none of the mechanics in my area can seem to help me identify it...I am going on guesswork now. My post is in the troubleshooting section-- "Need help with diagnosis."

Although I have a running bike with compression, I still have an awful ticking noise. I replaced the exhaust rocker, but still have same noise (you would think it should have at least gotten better?). Probably going to replace the camshaft and other rocker arm, and maybe take of the head and inspect the valves---I am wondering about the valve seats being worn....

Anyhow, reading this post has helped me a lot in terms of making sure the TDC is the TDC. I too, had been going by the T mark in the site glass, which Suzuki mechanics told me they don't even rely on. I have mine in the correct position, so I am going after looking for some worn out part.....I don't know....

[JohnC]

(you would think it should have at least gotten better?).
Consider the possibility you are barking up the wrong tree...

[plato1]

To John C......Yes, I agree.....It may or may not be the noise....I will be going into the head to check the valves....maybe even pull the cylinder off as there may be possibility of a piston issue....I don't know.....What I do know, is that it's going to keep coming apart until I find the issue causing the noise.....I just hope that doesn't lead me to new issues being created due to taking it apart and during reassembly.....Ugh....

[Goose51683]

All,

Thanks for keeping up on this thread. Life and work has caught up to me lately and I haven't had a chance to even touch the bike in months now. Looks like I will be disassembling the bike to do a total overhaul or I'll be finding a mechanic to get me back and running.

Then I can get back to what I really enjoy, customizing!

[jonathan180iq]

That's probably your best bet at this point, just to get the thing operational.

[Goose51683]

Yeah I'm just going to drive myself crazy at this point. Glad to see your all around still.

[jonathan180iq]

Pfffft.... We are the core. We don't go anywhere. It's the shady members like you that waft in and out out of our lives like a cool breeze in the Summertime...

[Goose51683]

Wow, harsh...I'll try to be a little more active for awhile. Hopefully i'm buying a new house here in the near future so I may slow down when that happens. On the plus side, it has a garage so I can quite losing nuts, bolts, and screws in the grass.

[Water Warrior 2]

A house means a Honey Do list to keep you away from doing things you want to do.

[jonathan180iq]

Wow, harsh...I'll try to be a little more active for awhile. Hopefully i'm buying a new house here in the near future so I may slow down when that happens. On the plus side, it has a garage so I can quite losing nuts, bolts, and screws in the grass.

Maybe I should have put a winky on that one... ;)

[Goose51683]

No I would just assume your being a jerk....;)

[Goose51683]

Just kidding John.

And yes, house means exactly that...so does, wife, kids, work and "so does life after 30"

Someone please tell me retirement means "freedom to finally act like a kid again and play however you like, whenever you like"

[alantf]

No......it means "Now you've got nothing else to do - this needs fixing, that needs fixing. And while you're at it - get out from under my feet" :whistle:

"Yed dear, no dear, threebags full dear"

[Goose51683]

Thanks for brightening my day Alantf

[Water Warrior 2]

No......it means "Now you've got nothing else to do - this needs fixing, that needs fixing. And while you're at it - get out from under my feet" :whistle:

"Yed dear, no dear, threebags full dear"
Just too funny Alantf.

Gotta agree with being old and retired with the option to do whatever I want whenever I want. My health is my wealth at this stage of the game. Life is good.

[Goose51683]

Anyone ever read that book "the 4 hr work week" Totally off subject but it's to cold to work on my bike at the time.

[jonathan180iq]

I haven't read it, but that's about as much real "work" I do at my place of employment and I'm considered one of the more productive and efficient ones. Not even joking.

[Goose51683]

I'm the opposite, I can literally work 50 hrs and I'm still expected to do more. It's a real load of bullshit since my boss has pretty much said that he's not doing any on call and he leaves early and comes in late most days.

[jonathan180iq]

What's the premise of the book, cause I may be off completely?

I was a business student for a long time and there are several trains of though on the matter, from what I recall. I think it's industry dependent obviously, but one of the ideas, especially in office work, is that the amount of time spent doing actual, real, quantifiable "work" is not that much at all. Whereas in more labor oriented jobs, which produce quantifiable work on a consistent basis for more hours than one should be required to give, the amount of down time and space for emotional and psychological and though development and stuff is really lacking.

[Goose51683]

I just started the book a little while back but it sounds a bit like what your talking about. concentrating on cutting out all the clutter and wasted time such as replying to pointless emails, and spending time on "work" that really has no benefit. Pretty sure my 50+ hrs could be cut down to about 4 when I look back at the week and think what did I actually get done this week.