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Discussion Starter #1
Hey all,

First time doing a valve adjustment on my 03 600rr track bike. Got to say....this is quite the process (my first time !). I am presently done pulling all the buckets and the old shims. I measured all the old shims using my mastercraft digital caliper and i noticed that the reading is off by a bit for most of them. Example: shim reads 190 but im getting 188.

In all cases my reading is lower than what was written on the shim. Is this normal as they are old shims and they get worn out? Or should I be using the stated measurement regardless.

Would like any help as this is my last step before calculating what new shims I require.

Thanks!
 

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I would get some shim stock of known thickness (use your shim stock pack if you have one) and check the accuracy of the calipers you're using. If the shim is stamped 190, it should be 190. Under bucket shims should not wear down.
 

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Discussion Starter #3
Thanks for the reply.

What I was thinking. It seemed odd that I was reading slightly smaller, it must have been my tool or measurement that was slightly off.
 

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If this is for your track bike then I would suggest you set the clearances at the upper limits of the adjustment range.

I've just had a race motor refreshed by a top engine builder (Chris Mehew) in the UK and he has also actually set mine slightly wider than a street engine. But it does have a skimmed head and a porting job, with race valves and springs.
 

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CBRCHRIS
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Go 0.03 tighter on intake and 0.04 tighter on the exhaust side and also upgrade your stock springs they tend to have valve float at high rpm. Do this will increase air flow by 18.5% on intake and 21.2% on exhaust side. Valve adjustments are crucial to power and tq even slightly out shims may not make any valve noise yet but the worn shim is reducing air flow, your valves only open a tiny amount even when adjusted properly. Most owners have no idea how valve clearance maintenance effects HP greatly.
 

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Chris, just so we're all on the same page here;

When you say tighter do you mean a thicker shim? The valves will open slightly more?

Sent from my Moto Z (2) using Tapatalk
 
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