Valve shim diameter

[Neophyte]

Kind of a dumb question I think. Can 7.48mm diameter shims be used for a Gen 1's valves or does it HAVE to be the 9.48mm shims?

Having to do the shims as I had the head apart to clean all the crap off the valves and from the ports, then lapping the valves (by hand).

It's my first time ever doing valve shims on a bike and was surprised to see it's not a part that you can readily buy at any bike parts shop. I do have someone sitting with a Hot Cams set which has all the thicknesses I need but they are 7.48mm diameter.

 

[c10]

9.48 mm why not measure the shims you have ?

 

[sixpack577]

No, you must use the correct diameter shims.
Measure what you have, they all may be in spec, if not, sometimes you can get lucky and swap shims to different valves, and get the height/gap correct on both after.
Otherwise, you will have to order the correct thickness shims, and in the correct diameter.

 

[Berlin Germany]

Can 7.48mm diameter shims be used for a Gen 1's valves or does it HAVE to be the 9.48mm shims?

hmmm - counter question - would you seriously want to try tightening a 3/8" screw with a 1/2" wrench?

or do u guess a 6mm screw can be fastened in a 8mm inner thread ?

damn ......

 

[GIXERHP]

9.48

 

[turtlezx]

buy a set of 9.48 shims ebay like above