Denis,

Thanks for the info: I have heard about the need for thermal cycling - it just sounds a bit brutal for a new engine. Anyway, I am going to take your advice - what you have written sounds very sensible based on my knowledge of engines and metallurgy.

I have a new MVVS 91 in its box waiting to go in an Edge 540 so I will be giving it your treatment. That is despite the supplier's (Just Engines) recommendation to start off 1/4 throttle and rich.

Thanks again for the advice: I'll let you know how it went.

Cheers,

Mick.