Shims

andyb1962 · #1 PostAuthor: **andyb1962** » Tue Mar 20, 2012 8:54 pm

i have recently changed a couple of valves and fitted a new cam chain.
Pete at RTT recommended i recheck shims at 600 to 1000 miles.
The valves were fitted with 250 shims and .05 gap
Checking and changing shims will not be an issue, (touch wood ...!) but my question is does the gap generally open up or reduce. (bigger or smaller shims?) Obviuosly it will depend on which face wears most but is there a general rule of thumb?

thanks guys :wink:

Z1parR · #2 PostAuthor: **Z1parR** » Tue Mar 20, 2012 8:57 pm

They wear tight , so smaller shims needed

andyb1962 · #3 PostAuthor: **andyb1962** » Tue Mar 20, 2012 9:07 pm

Thanks for that Geoff, So would it be fair to assume i am better off shimming the gap to the top end of the spec i.e. 0.1mm rather than 0.05mm.
Also depending on where you read spec is either 0.05 to 0.15mm or 0.05mm to 0.1mm any thoughts
thanks

Z1parR · #4 PostAuthor: **Z1parR** » Tue Mar 20, 2012 9:14 pm

Yes Andy thats basically the way to go , but the motor may at first sound a bit top end rustley until it warms up and then quietens down .
My Kawasaki manual says 0.05 to 0.10

zed1015 · #5 PostAuthor: **zed1015** » Tue Mar 20, 2012 9:16 pm

Always go wide.
Up to .18 if racing.
Between .10 and .15 for road.

jimmock · #6 PostAuthor: **jimmock** » Wed Mar 21, 2012 5:02 am

Z1parr wrote:They wear tight , so smaller shims needed

Due to valve and seat wear.

Valve seat receeding into head.

Jimmock.

#7 PostAuthor: **Ginger Bear** » Wed Mar 21, 2012 7:30 am

The club offer a 'shim swap scheme' to paid up club members, just contact Jerry & he'll swap 'em for free! :sou

Shims

Shims

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