Thanks for the tips guys. I followed your advice and the engine is now running so close to spot on its not funny. It still has what I think is a very very slight knock however I could be wrong. I mowed long grass with this machine for 20 off minutes today and short of one very small cough from the engine it didnt miss a beat. It stops and starts relatively easily and doesnt blow any smoke apart from a minor puff on startup. This engine actually has plenty of power. I know some dont like them but they are a pretty sweet machine when you get them running right.
When I come across a 4 stroke engine that is viable to completely rebuild I guess we will cross that bridge accordingly.
Unless anyone else has something to add I think the thread can be closed.
