Valve Shim Diameter Differences

I'm going from the stock 185 to 180 valve shims on the exhaust valves. My Yamaha Dealer was out of OEM shims. He found a couple of 180s that were loose, indicating that they came out of a motor and were saved. When comparing the stock 185s to the 180s I noticed the diameter was about 60% of the stock ones. Doesn't look like it could slip out of the cradle but just want to know how particular this needs to be.

Get the hotcams kit. Best value and they will fit properly.

Don't use 'em, they don't fit. Used shims will not change diameter. Any dealer that also has a service department should be able to give you any shim you need, that is for your bike.

If you do use 'em, take pictures. I wanna see what happens!

The smaller diameter ones are most likely 250F shims. Use the right size shims. All of the Japanese 450's use the same shims, so you can get the shims you need from any Yamaha, Honda, Suzuki, or Kawasaki dealer. If one dealer doesn't have any, go to another.

the "don't use 'em" advise was the best. turns out, the dealer gave me the 250 shims, using them would have been bad. valve/piston job completed, runs like new. thanks for saving my a**

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