Piston and Cylinder Bore

the KZ550

Piston OD 57.80mm
Bore 58.10mm

KZ400
piston OD approx 52mm

too much of a difference i think..

Where did you measure piston diameter? They are always narrower at the top and wider at the bottom. I recall at the top where the rings are, there is about a .006" gap to the cylinder wall.

not far from the bottom, i also looked in the manual. which says pretty much the same

bountyhunter wrote:

Where did you measure piston diameter? They are always narrower at the top and wider at the bottom. I recall at the top where the rings are, there is about a .006" gap to the cylinder wall.

And wider measured across the pin than perpendicular to the pin.

Makes for an odd shape piston when you think about it.

Just measured a Wiseco 810 piston to verify.