(new owner) Valve clearance (strange)

[TGR]

I bought my first GS500EX just over a fortnight ago and just after I bought it, it developed a problem running/idling. So went throught all the normal steps of stripping/cleaning carbs, air leaks etc etc and not alot changed!  so I moved on to Valve clearances and the results seem to be alittle strange. I checked the clearance and had less than 0.05 on each shim, so time to rip them out and see what shims I needed:

(view from riders seat)

OUT:

Shim 260mm, real thickness 260mm. ----------------- Shim 260mm, real thickness 265mm.

IN

Shim 262mm, real thickness 255mm. ----------------- Shim 255mm, real thickness 260mm.

As you can see it does'nt really make alot of sence, where the bike managed to get a 262mm shim I dont know as I thought shims went up in 0.5's?m and hello everybody 

[beRto]

I bought my first GS500EX just over a fortnight ago and just after I bought it, it developed a problem running/idling. So went throught all the normal steps of stripping/cleaning carbs, air leaks etc etc and not alot changed!  so I moved on to Valve clearances and the results seem to be alittle strange. I checked the clearance and had less than 0.05 on each shim, so time to rip them out and see what shims I needed:

(view from riders seat)

OUT:

Shim 260mm, real thickness 260mm. ----------------- Shim 260mm, real thickness 265mm.

IN

Shim 262mm, real thickness 255mm. ----------------- Shim 255mm, real thickness 260mm.

As you can see it does'nt really make alot of sence, where the bike managed to get a 262mm shim I dont know as I thought shims went up in 0.5's?m and hello everybody 

The 2.62 mm shim was likely installed at the Suzuki factory. The factory has shims in all sizes; us mortals can only purchase them in 0.05 mm increments.

How are you measuring the "real thickness"?  Your measured thicknesses seem to be too far off from the original thickness? 

[TGR]

Just using a set of vermier caliper's, I thought it was very unlikey that they could be out that far, but I've checked and checked again and still end up with the same results.  But I can't rule out the calipers being aload of crap, I'll source another set and check again. But i've ordered a set of shims so it shouldnt really matter

EDIT:
I switched the two inlet shims around, fitted the indicated 262mm into the 255mm valve seat and I got a 0.05 clearance, but using the 255mm indicated shim in, I had no clearance atall. 

[bucks1605]

where did you order your shims?

[beRto]

Just using a set of vermier caliper's, I thought it was very unlikey that they could be out that far, but I've checked and checked again and still end up with the same results.  But I can't rule out the calipers being aload of crap, I'll source another set and check again. But i've ordered a set of shims so it shouldnt really matter

It seems especially suspicious that one of your shims got thicker. 

EDIT:
I switched the two inlet shims around, fitted the indicated 262mm into the 255mm valve seat and I got a 0.05 clearance, but using the 255mm indicated shim in, I had no clearance atall. 

I'm confused. So, referring to the same valve bucket, a 2.62 mm shim (indicated) resulted in a clearance of 0.05 mm, but a 2.55 mm shim (indicated) gave 0.00 mm clearance?

Are you turning the engine over between shim changes to force out all of the oil behind the shim?
Which procedure are you using for the valve check (Haynes, Clymer, Suzuki, other)?
Are you checking the clearance with the cam in the right position?

[The Buddha]

Yea factory has shims in increments os 1, however they use it very poorly and throw in shims that let your clearance bee close to too high or too low. You'd think they will aim for an exact number right in the middle. Like 2 thou ... nope.
Now maybe you're misreading the number on the shim cos its been worn, I ahve measured a 1 thou fatter maybe ... like a 255 is a 256 ...
Anyway since we are measuring them, we also ahve access to all thicknesses  .
Cool.
Buddha.

[TGR]

where did you order your shims?

Before I hit the order button I noticed  that wemoto only stocked 29mm shims rather than the 29.5mm I need  

I'm confused. So, referring to the same valve bucket, a 2.62 mm shim (indicated) resulted in a clearance of 0.05 mm, but a 2.55 mm shim (indicated) gave 0.00 mm clearance?

Pretty much so.

Are you turning the engine over between shim changes to force out all of the oil behind the shim?

Yes.

Which procedure are you using for the valve check (Haynes, Clymer, Suzuki, other)?

Kerry valve clearance video and the not so good haynes manual.

Are you checking the clearance with the cam in the right position?

See above.

[TGR]

Here's my 255 valve shim:



diameter:


thickness:


I've checked five times now and it still tells me that the shim marked 255mm is a 260mm 

[bluespy]

TGR, It sounds like your calipers are correct, given the test you did swapping the intake shims.  Your 2.55 is thicker than the 2.62.  Is this what you have decided?

[TGR]

Yea, cause the 262mm is reading a thickness of 255mm. Hence why i did the diameter of the valve shim cause if the calipers where over reading the diameter would of been 30mm. But I'll see if i can track down a place in the UK or the States that sells a shim kit and get it all sorted that way.