Hi All,

During a bit of routine airframe servicing yesterday I noticed that my YS160 had a very small amount of end-float in the crankshaft i.e., it was possible to push/pull the shaft in/out rather than any side to side movement. Very small amount, but enough I could feel and hear it. It needed a fairly firm push/pull to make it move. This prompted me to put the tacho on it which I hadn't done for ages and it's down at about 7600rpm on a 17x12 APC, 30% OptiFuel YS, sea-level, hattori rigid header and long pipe. Everything else is fine, ticks over/runs/transitions well, also replaced plug and checked for leaks and checked valve gaps.

Given that it has a disc valve in the back, I'm thinking this is not good. Is it normal?

Cheers,

A