Troubles with my GZ's engine, please assist.

[bergreen]

Hey guys, I'm new to this forum. Guess I'll start off with a bit of introduction. My name is Daniel and I've owned my 2008 GZ250 for 6-8 months now. She's my daily commuter (30 miles a day or so) and has taken me on a few road trips that average 300 miles round-trip. Kinda hard on this little motor. She has about 8,000 miles, regular oil/filter changes, clean and lube the chain, wash the bike, etc. I usually use mid-grade gas, and always give her Suzuki performance 4 10W40 oil as suggested. I just replaced the spark plug a couple days ago.

Now on to the issues. I got in a minor wreck over Christmas vacation. Some guy in a truck went very far out of his way to make sure I hit him, but that's an entirely different story. Hit his bed with my left handlebar and dropped it on the right side. No tilt sensor - brilliant - so the bike kept running. I had her standing up again in less than 10 seconds, so I don't think there was much damage as far as having the bike running while sideways. Brake pedal was bent, fender/tank/muffler scratched, front right blinker mount got bent. That's about the extent of the cosmetic damage.

Here's the engine trouble. I'm not sure if it is related to the wreck, but I figured I would include that story just in case. I will list out the problems in bullet form.

1) High-pitched whiny sound from the engine while at cruising speeds.
2) Feels off-balanced in the back.
3) Front forks and steering column are not perpendicular to the frame.
4) Backfiring out the intake/airbox when cold (probably needs a valve adjustment).
5) Slipped the clutch, hearing a metal-on-metal sound from that side, cannot recreate the sound now.
6) Noticed a small leak from the front-right of the base gasket.

Any ideas?

[bergreen]

Oh also the old spark plug looked good, burned at a nice light tan color.

[blaine]

Welcome.Your bike not tracking properly,feeling unstable,and the whining sound,sounds like your back wheel is not running straight.Your base leak will probably need retorquing the bolts on the pan,or a new gasket.I think you are right about the valve adjustment.You can check your wheel alignment by checking the marks on each side of the frame.
:cool: :)

[Water Warrior 2]

2 quick questions. Did you do any damage to the clutch lever when you hit the truck ? Is there any damage or bending done to the handlebars ? Either side higher or lower, further forward or back ?

[bergreen]

To answer water warrior, no damage to the shifter, no damage to the handlebars.

To address the balancing issues, my alignment is fine, and it has felt imbalanced since the day I got it.

Thank you guys for the fast responses.

[jonathan180iq]

Backfiring and popping is more likely that when you wrecked a vacuum hose may have pulled loose under the tank. (Since you did mention the tank being hit, i's worth looking at.) Pulling the tank is all of 3 bolts and 5 minutes. Do an inspection under there to make sure that all hoses going into and coming out of the carb are securely attached and not road rashed or something funny.

Everything else you mentioned needs a once over. Are you saying that your forks and handle bars aren't lined up properly when you hold them straight? Like when you misalign your handle bars after biffing it on a bicycle?

Stand back and have someone slowly roll the bike forward in a straight line to make sure everything is lined up the way it should be, back to front.

[bergreen]

No I mean when I'm riding in a straight line, my forks and steering column are angled slightly to the right.

[blaine]

No I mean when I'm riding in a straight line, my forks and steering column are angled slightly to the right.
Was the forks like that when you bought it?(you said it felt unbalanced since you bought it.)or just since the accident?It's starting to sound like the forks are bent,or the frame is twisted.Either way,it shouldn't be rode till you find the problem.
:??: :whistle:

[Water Warrior 2]

No I mean when I'm riding in a straight line, my forks and steering column are angled slightly to the right.
Hmm, I need a better explaination of steering column. Are you referring to the steering head that is a solid part on the front of the frame ?

[alantf]

I usually use mid-grade gas,

Hi there,
Don't waste your money. The geezer's designed to run on cat's piss if necessary. Just go for the lowest grade you can get. :2tup:

[jonathan180iq]

No I mean when I'm riding in a straight line, my forks and steering column are angled slightly to the right.

When it's like this, is the tire still straight?
Either way, this is a pretty big deal.

[bergreen]

It has been like that since I have bought it, the forks are straight, I'm still riding in a a perfectly straight line (even when I let go of the handlebars entirely). While I'm sitting on the bike, every front-end component I can see (forks, steering column, triple tree) is angled to the right about 5-10 degrees.

[jonathan180iq]

Well then your frame almost has to be warped, prior to your most recent accident.

I can't see how your whole front end can be off at almost a 10 degree angle and you be able to ride in a straight line without your forks also being twisted back the opposite directon to keep the tire straight.

Do you feel like the bike is "heavier" on one side than the other? Does it pull if you don't counter balance with your weight? Are you getting any kind of uneven tire wear?

The only other thing I can think of is that there is an optical illusion that can take place if you look at the bike from the front. The side with the rotor/caliper can make the forks look off-center from the right angle. Are you certain it's not just something like that?

[bergreen]

Yeah I'm certain. Honestly I'm not worried about any of those things. What I'm worried about is the cluth - or what I thought would be the clutch. I pulled off the side cover and couldn't see anything wrong. Oil looked fine, althought it faintly smelled like gas. Saw nothing in the bottom of the case. Now I have to do more in-depth diagnostic, and all I got out of it was 5 hours wasted scraping a gasket that was baked on.

Onequestion though. What is the torque spec on the front sprocket? My 16t just came in

[blaine]

One question though. What is the torque spec on the front sprocket? My 16t just came in
Torque is 40 f/lb,Or good and snug with a 1/2" ratchet.It is more important to make sure the lock washer is installed,and bent over,so the nut cannot back off.
:) :2tup:

[jonathan180iq]

Yeah... Just get it good and tight and then lock the tab down.

[bergreen]

Figured out what happened with the clutch. The last friction plate (the one closest to the inside of the engine) rubbed. It's burred and almost polished. I'm not entirely sure how this would happen. Any ideas?

I also found out that my clutch basket actually moves a little (about 1/4th inch free play) side to side on the gear. Is it supposed to move a little?

Please help, I need this fixed within a few days...

[bergreen]

And now the front sprocket bolt will NOT come off. Yes, I got the lockwasher bent back in place flat. Yes, I'm locking the rear brake. Yes, I tapped it with a hammer to shock it loose. Nothing. Getting really tired of this pathetic POS. Can anyone offer any assistance? Need to get this thing back into shape immediately.

[blaine]

And now the front sprocket bolt will NOT come off. Yes, I got the lockwasher bent back in place flat. Yes, I'm locking the rear brake. Yes, I tapped it with a hammer to shock it loose. Nothing. Getting really tired of this pathetic POS. Can anyone offer any assistance? Need to get this thing back into shape immediately.
I assume that you are turning it to the left? :??: You may need to shock it loose with a impact gun,although I have never seen a sprocket nut that tight. :)

[bergreen]

Yes I'm turning to the left. I'm a certified mechanic so I know what I'm doing, I just don't have the experience of working in a shop yet. Still finishing up school, so I don't know all the little tricks to get difficult things done.

[blaine]

Yes I'm turning to the left. I'm a certified mechanic so I know what I'm doing, I just don't have the experience of working in a shop yet. Still finishing up school, so I don't know all the little tricks to get difficult things done.
Sorry,didn't mean to offend you in any way.Some people don't have the experience to know.As I stated a impact gun may be needed.Just a thought,someone before you may have put loctite on it.If it is red loctite you may need a little heat.
:) :cool:

[Water Warrior 2]

Will trade frustrations with you. I'll get the sprocket off if you can mount my new camera on the Vstrom. I'll get serious now. Just to be sure which way to turn the sprocket nut. Counter clock wise is loosening the nut when you are facing it. Now, what are you using for tools ? Nothing less that a 1/2 inch drive and a socket or a man sized wrench will be effective for the force needed. An impact tool would be a bonus if you can borrow one.

[Water Warrior 2]

Yes I'm turning to the left. I'm a certified mechanic so I know what I'm doing, I just don't have the experience of working in a shop yet. Still finishing up school, so I don't know all the little tricks to get difficult things done.
No insult intended here either. Tricks of the trade will come with experience and time. The little GZ will be a willing teacher to help your learning curve. You will get her done.

[bergreen]

You guys told me the torque spec for the front sprocket nut is 40 ft/lbs but the service manual says 65. Now the service manual I downloaded from this site is old and isn't for my '08, so it may be out-dated.

Can you guys tell me what is the correct torque spec for my 08 GZ250's front sprocket?

[blaine]

The manual is correct for all models,or good and snug with a 1/2" ratchet.It is more important to make sure the lock washer is installed,and bent over,so the nut cannot back off.I thought it was 40 ft/lbs as I don't own the G.Z. any longer.How did you get the nut loosened? :??: :)

[bergreen]

Just waited for one of my roommates to get back. Had him stand on the brake so I could just stand next to the bike and get a good grip on the ratchet.

Now I hope the parts I ordered for the clutch were the right ones. Really need to get this bike up and running, I don't have another vehicle =(

I wonder if maybe you've seen this or a similar problem before. One night I pulled in the clutch lever while the throttle was wide open (whoops), it slipped and started making this metal-on-metal scraping sound. It got progressively worse as I got closer to home. As I was pulling into the driveway it was making a pretty nasty grinding sound. Fast-forward through the story a bit, I took apart the clutch. What I found was that the very last plate (the friction plate that sits at the base of the basket, closest to the engine) had rubbed. The plate's "teeth" that sit in the basket's fingers actually rubbed against the basket itself. All the other plates are fine, except a little bit of rubbing around the outside edge of a couple metal plates. So I looked at the wave/diaphragm spring that sits inside the basket behind all the plates. It was almost flat, and slightly warped. It seems apparent that this would be the cause, as it was neither keeping the plate flat nor level.

So I ordered a new wave spring, wave spring seat, and that one plate. I know I should have replaced all the plates, and probably the four springs too, but I'm broke. I received these parts in the mail today, and I plan on installing them tonight. Unfortunately I don't have any oil, so I can't take it for a test ride. However the stall on the ride provides an opportunity to ask additional questions.

1) Is this a common issue with slipped clutches?
2) Might there be an underlying issue that caused these parts to warp?

[blaine]

When I replaced the clutch on mine,I replaced the discs & the outer pressure springs.I had no other problems.My bike had 32000 kms on it and the rest of the parts worked fine.When I sold my G.Z. it had 46000 kms on it and the clutch still worked fine.
:) :cool:

[bergreen]

After all that work, it's still making that same noise. Took it for about a 3-4 mile test ride below 40 mph through my neighborhood. I think I'm going to take her out on the road and see what happens.

[bergreen]

Great, even with the new parts it happened again. What the hell could make the last friction plate rub up against the inner hub like this?!

[blaine]

Great, even with the new parts it happened again. What the hell could make the last friction plate rub up against the inner hub like this?!
This is only a guess,but I'm wondering if the basket itself may be warped? :??: :)

[Shammua]

With you saying that the front end seems to be about 10 degrees off even if your going straight and now the clutch rubbing issue (due to warping it seems) I would have to say that over all this bike has been wrecked and the frame is bent. The bend in the frame can cause stress that over time can cause warping of components such as the clutch basket and so on... I am not an expert on this bike yet but to my way of thinking and with the signs and symptoms you are providing that would be my first educated guess. If you can try doing a side by side with someone that either has the same bike or at least one as close to the same as yours. Sometimes a visual comparison helps to see small discrepencies that weren't visible before.

I have used this trick many times with my old Jeep Wrangler when it was messed up but I had no clue what was wrong. I would have a buddy ome over with his and I would jack both up and slide back and forth under them and in the end I discovered that not only did I have some missing bolts, but also my transfer case shifter hadn't been attached properly, OR braced into place as it should have been. Once I got these issues fixed on the Jeep it ran smoother, quieter, and my leak went away.

I know bikes are a lot different than any 4 wheel vehicle but the troubleshooting technique can be used the same...
I hope you find what is wrong and I honestly pray that I am wrong on the bent frame analysis...

Sham