Shim Size Formula

[dx400r]

Can anyone recall the formula you need to do in order to work out what shim size you need?

As an exercise I am writing a C# app that does this leg work but am approximately 23 miles from my haynes book, being at work and all.

To top it all off, this program and the source shall be released on 400 grey bike when its all done! How about that! :D

[CMSMJ1]

Well..

If you have a valve that is at 0.20 (inlet) and you want it to be 0.15

It has a shim in already... 2.25 then you need to fit a 2.30 shim to close it down.

figure that out

target = .015 (or 0.12 - 0.18)
current = 0.20
incummbent shim = 2.25
required shim = 2.30 (or a range 2.27 - 2.33)

that seem right ? You don't need a program to work it out anyways...it become intuitive as you do more of it

[oliherst]

(Lifted from Haynes manual:)

a=b-c+d
where:
a = required shim size
b = measured valve clearance
c = specified valve clearance
d = existing shim thickness

[dx400r]

Its more a learning exercise for me than anything else . Might be useful for some tho!

[sa.racing]

The formula your looking for is, Shim size + measured clearance - desired clearance EG: Inlet valve with a 2.33 shim fitted and a measured clearance of 0.08 and a desired clearance of 0.15
2.33 + 0.08 = 2.41 - 0.15 = 2.26
Make sense ?