Question about valve shims...

[jdion81]

Well, that was weird. But I think I figured it out. I decided to try another valve with the 2.0 shim, found the suggested shim of 2.6. Installed the 2.6 and rechecked and it was good. I decided to then check the 2.35x shim with calipers and it measured to 2.5. What the heck? I kept on going and was able to shuffle shims and get 4 valves within spec. I need to trade out some shims and finish it up.

Has anyone ever had a shim not measure the same as it was marked, I mean how would it be thicker than it was marked? I can understand it being thinner, it could have been polished.

[hannibal]

I always measure both thickness and diameter. I started this after getting 29mm shims from the box marked 29.5mm at my local dealer.

[chuck hahn]

Yes I measure each one and have found many that were different than marked. Also, when you install shim out them into the bucket with the number facing down..not to the cam side. This keeps the cam lobe from wearing numbers off the shims.

[Burque73]

Well, that was weird. But I think I figured it out. I decided to try another valve with the 2.0 shim, found the suggested shim of 2.6. Installed the 2.6 and rechecked and it was good. I decided to then check the 2.35x shim with calipers and it measured to 2.5. What the heck? I kept on going and was able to shuffle shims and get 4 valves within spec. I need to trade out some shims and finish it up.

Has anyone ever had a shim not measure the same as it was marked, I mean how would it be thicker than it was marked? I can understand it being thinner, it could have been polished.

As others have stated I've found shims inaccurately marked too. Also, I've had feeler gauge readings that didn't add up after changing shims. Too much oil can be trapped under the shim giving a false reading so rotating the crank lets the cam lobe squeeze out excess oil, then an accurate measurement can be taken. Maybe stating the obvious here but didn't see this mentioned so just thought I'd add it.

[jdion81]

I have been making sure to turn the engine a couple of times to make sure that the valve is opened a couple of times and seat the shim. My problem in measuring the shims is that my calipers will only go to tenths of mm.

[chuck hahn]

I got digitals from harbor Freight for less than 25 bucks.

[fixmybrokecomputer]

I have been making sure to turn the engine a couple of times to make sure that the valve is opened a couple of times and seat the shim. My problem in measuring the shims is that my calipers will only go to tenths of mm.

To accurately measure the shims, you need to use a quality micrometer. Vernier calipers are not the best choice for the job. Hope that helps.

[jdion81]

Chuck, how precise are the ones that you got?

I got digitals from harbor Freight for less than 25 bucks.

[storm 64]

To accurately measure the shims, you need to use a quality micrometer. Vernier calipers are not the best choice for the job. Hope that helps.

+1 I agree. I never use Vernier/Digital Calipers at work...

[jdion81]

Be sure you are using the Suzuki manual procedure. Type of feelers matters little. If a 2 mm shim still has zero clearance, you may need to replace seats, replace head or try trimming valve stems a bit. Know where you are before doing any of these things. Let me know if I can help.

Ray, I finally figured it out. I sent you a PM with a list of shims that I would like to swap with you.

[Motojoe2492]

I'm going to follow this thread, I will be lapping my valves soon and want to get as much info as I can!

[John Park]

I always measure both thickness and diameter. I started this after getting 29mm shims from the box marked 29.5mm at my local dealer.

I've never used 29mm shims, but you have to wonder if they would lead to a cam walk sound, or other forms of racket. I've been handed 29s from a dealer who doesn't bother to differentiate.

I once wondered what it was they fit, but whatever it is, I don't own one - or plan to. I now just buy new GS500 shims because on a twin there are only 4 shims anyway.

[Nessism]

I went to a local dealer one time and after asking for some shims they handed me Kawasaki shims which are smaller. Told them I don't want them and the guy looked at me crooked and said they install them into customer bikes all the time.

[bobgroger]

Are you doing this with the head off or on and properly torqued? If the head is off you are only getting it close as things will change with the compression load of the studs. Get it close, then do it again when it is all back together.

[Steve]

I've been handed 29s from a dealer who doesn't bother to differentiate.

I once wondered what it was they fit, but whatever it is, I don't own one - or plan to.

29.0mm shims fit the KZ bikes that I had and some Yamahas.

I have a modest selection of them, because I have had three KZs and one ZN bike.
I make sure they are kept nowhere near my 29.5mm GS shims.

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