Valve Clearances - incorrect??

[Glyn]

Hi all

Just measured the clearances on the bike. 4 of the 8 were within spec, 4 out. Funny thing is all the ones which were out were too small, eg rear inlets both .0035 inches.

I was thinking, is it possible for a thin layer of oil to get between the shim and the carrier and distort the readings? If so it would tend to close up the gap. When the cam / shim wears I would think the gap would always get bigger, not smaller. Does this sound logical??
It could be of course it has the wrong shims  in anyway.

I suppose, take them all out, de grease and try again would be the test?

Any advice/ thioughts on this?

Cheers

Glyn

[louthepou]

It ain't weird - in fact, it's normal.

The valve wears out slightly with time, just around its perimeter (near the seat). So, it's getting thinner. The whole valve gradually is closing the gap between the shim and the cam lobe.

Cool!

Louis

[Glyn]

Thanks for that Louis. Yeh now it makes sense. At least the valves are acting normally.

Cheers

Glyn