Valve Noise in GS Twin

[suzukizone]

Although the bike is a 2000 GS500E the valve train should be idtentical to GS400 & other GS's. 16,500 miles. Bike runs very very superbly.

A loud metallic "snap" as if a shim was slightly out of position and slapped into place by the cam.

Occurs only on cold engine startup at lower temps (60's F & lower) First thing in AM or evening if bike sitting out in cooler weather. Will only happen once until engine has again gone dead cold.

Happens about 25% of the time under the described conditions.

Yes valve clearances have been checked over & over & over to the nth degree.

There is a small circular imprint on the head near the RH Exhaust valve that matches the imprint of a shim. Can't imagine the shim repeatedly jumps out of postioin & then nice & neat back into place but,......?

May have an image of the mark.

Also should I see scuff marks all over the shim buckets outer perimeter> This is on all 4 buckets.

Thanks

Douglas

[hampshirehog]

You have checked that it's the right diameter shims fitted in there? Could be floating a bit in the bucket if it's smaller.

[bwringer]

You have checked that it's the right diameter shims fitted in there? Could be floating a bit in the bucket if it's smaller.

Seconded -- GS shims are 29.5mm diameter, and it's not unknown for thumbfingered mechanics to drop in 29.0mm diameter shims intended for Kawasakis and Yamahas.

Results can be rather ungood.

[suzukizone]

Valve Noise in GS Twin

Thanks hampshire hog & bwringer. Wish that was it. Shims are either the orig Suzook ones or out of the Suzuki shim box at the shop( no Yam or Kaw shims there) or ordered from suzuki, depending on which valve clearance check was done. They fit tight & snug when seated.

I'm not sure the shim is jumping out but just tried to list any possible evidence clear or otherwise.

This situ has gone on a few years & drives me nuts. My shop says not to worry which is a sentence that always makes me worry even more.Isn't that what one dinosaur said to the other as they watched the asteroid approach???
Thanks, still open to any & all ideas.

Douglas

[Nessism]

Sounds normal but then again we can't hear the engine. How about posting a video file with sound?

[suzukizone]

http://www.thegsresources.com/_valve noise in GS Twin

Thanks Ed but,...
wouldn't even know how to create such a thing but even if I did, bike is now in another state as going to a family member, is a bit torn down (camshafts & buckets out, and it is a irregular event which is also related to low temperature.

Yeah I wish I had such a thing as I figure it would ring a bell with someone.
I do appreciate your input & any else that is out there.
Douglas

[GregT]

My 2c worth is that you probably have a sticking exhaust valve. The 180deg twins tend to stop in one position when switched off and this is usually with one exhaust valve open, In damp weather if the bike is left for some time the valve can stick when the motor first turns over.
Your mark in the head is probably where a shim has jumped out previously - it's possible there is a bent valve there.
I've done a lot of work on the older DOHC Jaguars which suffer badly from stuck valves when they're left to sit - if you think yours makes a noise you should hear a Jag with this problem - and see the bill.....

Greg T

[suzukizone]

Valve noise in GS Twin

Thanks Greg T & all others. Will look at that sticking/bent valve issue when I next get near that bike which is currently out of state with it's future daddy.
DH