Hi Grumpy, did some accurate measuring and the belt had actually moved two teeth ( is it normal for the belt to be able to move so far or has my local mechanic not taken enough notice when putting it back together ). I marked the sprocket and belt with a white pen were they should end up after rotating sprocket ( in the right direction). Turned motor over by hand checking every compression stroke only, for a number of turns, all lined up perfectly. Put back together, decided once more to check carby ( nice and clean ), guess what, purred like a kitten at any speed, no cutting out under half throttle and no hunting. Please let me know if there is something I should do or haven't done or to keep an eye on for the next couple of mowing's.
Thanking you Paul.
