Need Help on 85' GS450L Engine won't start

[Anonymous]

Symton: All electric parts works fine, sparks on both plugs. The engine does crank over but won't start. Zero compression on both cylinders.

Cause: I was adjusting the cam chain tensioner. After remounted the unit on the engine block, I cranked the crankshaft to see if the unit was working properly. I accidently over cranked the crankshaft (counter-clockwise) and I heard some clicking from the top of the engine. Then I cranked it forward a little bit.
And then I did something I really should not have done. I tried to start the engine by pushing the ignition button. I heard the engine crank with some strange clicking noises, seemed that the cam chain is skipping, and of course the engine did not start.
Then I realized the timing was off, so I took apart the camshaft and adjust the timing. Now the timing is right, (if the correct cam chain pins between "2" on the EX camshaft and "3" on the IN camshaft is 19) when cranking the engine, there's no strange noises anymore, but the engine just won't start. I think I broke the valves so that there's zero compression on both cylinders.

I'm really so depressed cuz I bought the bike for only 3 weeks, before this tragedy it ran great, had only 8k original miles. Only the cam chain was making noises.

I know many of you are experienced on bikes especilly Suzuki GS series. Please give me some advices or help me to diagnose, I will appreciate very much.

[Anonymous]

check the valve clearances to see if they are stuck really open.

Steve

[Anonymous]

check the valve clearances to see if they are stuck really open.

Steve

Thank you Steve!
Will do it tomorrow. Just a quick (stupid) question:
If they are, will this cause zero compression ?

[Anonymous]

Yes. If the valves are open the air just squirts out, doesn't compress.

Michael

[Anonymous]

Yes. If the valves are open the air just squirts out, doesn't compress.

Michael

Thank you Michael.

I have not checked the clearances yet, don't have the tool "feeler gauge" to check them. If the clearances show that the valves are stuck too open, what should I do?

I read the chapter on the Haynes manual about the valve clearances. The way to adjust the clearances is to replace the adjuster shims (pads) on the 450 model. Is it the only way to do it without taking apart the cylinder head?

And another question: by any chance I broke / damaged the valves?

[Anonymous]

Swapping shims is the only way to adjust the valves on the 450. I miss my old cb650 with the screw/locknut adjusters... I'm in the process of rebuulding my 450L. I've bought a shim kit off of ebay and its on its way to me. You;ll likely need one to have a selection of shims to adjust your valves. Your other choice would be to trade shims at your local shop.

I suppose its possible that valves are bent or broken. Broken peices though would made a heinous noise; bent ones may just fail to close properly. If adjusting the valves doesn't boost your compression, you'll need to roll up sleeves and consider removing the head to see the valve condition for yourself. Its not that hard, I'm no mechanic and I didn't have too much trouble (of course my bike isn't actually finished and running yet either!)

Sam

Yes. If the valves are open the air just squirts out, doesn't compress.

Michael

Thank you Michael.

I have not checked the clearances yet, don't have the tool "feeler gauge" to check them. If the clearances show that the valves are stuck too open, what should I do?

I read the chapter on the Haynes manual about the valve clearances. The way to adjust the clearances is to replace the adjuster shims (pads) on the 450 model. Is it the only way to do it without taking apart the cylinder head?

And another question: by any chance I broke / damaged the valves?

[Anonymous]

Changing the shims won't help if the valves are bent. The only thing is that they have to be set within spec before you can do a compression test properly.

Steve

[Anonymous]

Well, I spent one hr to remove the cyl. head this afternoon. Looks like the valves are damaged. There are signs of impacts on the valves and the pistons. The pistons look OK though.
So I am thinking about taking the cylinder head to the dealer and ask them to fix the valves. Cuz for me it looks too difficult to remove them, and seems it requires some special tools.
Does anybody know a good place to purchase GS parts, like valves, gaskets...etc.?

[Anonymous]

Valves, and their guide seals, I think are suzuki only. There not cheap but look on the bright side, with a twin you don't need that many!
Also, now that the head is off, you've saved yourself a ton of cash in labour as opposed to having the bike itself brought in to the dealer.

As for gaskets, any local shop should be able to get them. It'll be cheaper to go with an aftermarket gasket kit. The kit costs about the same as just the oem suzuki head gasket! At least it does around here.

the best place to get parts varies by what your looking for. Personally I use the local Yammy dealer (the Suzzy guy is just too far away) and he's got catalogs with all kinds of stuff in them. 8)

Hard to find things can be found on ebay. Some online retailers have nice deals on items like tires.

hope this helps...Sam

Well, I spent one hr to remove the cyl. head this afternoon. Looks like the valves are damaged. There are signs of impacts on the valves and the pistons. The pistons look OK though.
So I am thinking about taking the cylinder head to the dealer and ask them to fix the valves. Cuz for me it looks too difficult to remove them, and seems it requires some special tools.
Does anybody know a good place to purchase GS parts, like valves, gaskets...etc.?

[Anonymous]

Thank you for the advice, Sam.
I'll take the cyl.Head to the dealer tomorrow. Let them inspect it first.

Engines are funny things, 2 hours ago it was still running 80 mph on the highway, 2 hours later, a little mistake, "boom" it's history.

[Anonymous]

Yeah, at least the exhaust valves are bent.
When turning the head upside down, i can see light coming from the gaps on both EX valves from the exhaust holes.
Valves are expensive, 40 for each.(ex) Sigh...now need to pay $200 for this stupid mistake i made. That's half of the price i paid for the bike. ~>_<~ what an expensive lesson.

[Dave_A]

Yeah, at least the exhaust valves are bent.
When turning the head upside down, i can see light coming from the gaps on both EX valves from the exhaust holes.
Valves are expensive, 40 for each.(ex) Sigh...now need to pay $200 for this stupid mistake i made. That's half of the price i paid for the bike. ~>_<~ what an expensive lesson.

Ebay

New Head

Problem solved for ~$50

Or you can opt for the expensive route & re-build your head, but if you do that you might as well re-build the whole top end (cyl hone, rings, etc)...

[Anonymous]

Ebay

New Head

Problem solved for ~$50

Gee! where do u find that head on ebay? I tried looking for it these days, but no luck. If you find it somewhere please send me the link, I'd appreciate that a lot!

[Dave_A]

Ebay

New Head

Problem solved for ~$50

Gee! where do u find that head on ebay? I tried looking for it these days, but no luck. If you find it somewhere please send me the link, I'd appreciate that a lot!

Check ebay now...

$30 buy-it-now

Head, valve cover, and cyls...

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=35595&item=7903155313&rd=1

[Anonymous]

Thanks a lot!
I contacted the seller, and he told me one of the ex valves is bad.


I just got an advice from a guy in the local cycle dealer. He told me to get a valve spring compressor and replace the valves by myself. A valve spring compressor costs $15, and the Autozone even provides free loan-a-tool service. I think this is a good way to save $$$.

So is there anything I should be careful for replacing the valves? (there are 4 of them.)