Tapered piston!

Hi Chaps,

I've removed the piston from my WR450 for inspection and have found it to be tapered. :thumbsup:

At the bottom it measures 95.00mm but at the top its 94.55mm.

That's a 0.45mm (0.018") difference. :p

Can anyone tell me if this is how it should be?

The only reason I ask, is, the piston only looks lightly worn.

If anyone has an unused WR piston that they could measure, to confirm, that would be very helpful. :lame:

Best regards,


I believe the difference is to accomodate the fact that when at operating temperature the top of the piston is slightly hotter and therefore expands more than the bottom, therefore the difference you measure when it is cold is balanced out.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now