Ive had the engine in bits. Looks OK (first nitro car engine Ive had apart though). A couple of very experienced racers also had a look at it and thought it looked OK too.
One of the guys said its very likely my setup. (clutch, two speed, tuning) Hope he's right and ill get it sorted.
Thanks for the advise.
QRCCRA, QLD Radio Circuit Car Racing Association, England Park Raceway, Brendale, Brisbane North, Australia.
RCORRSC, Radio Control Off Road Racing Sunshine Coast, (Mooloolah Valley), Australia.