im not sure how many ltrs you have put through your motor but to me i would start again with bothe needles flush warm it up a little and get a 6 sec pinch on the bottem end at idle, remember on the the gx series carbies 1/2 hour adjustment on the top end is huge no more then this at a time , i would how ever suggest you take aread of the massive mods web sight on tuning it may shed some light on the problems you are having check it out

http://www.massivemods.com.au/produc...roducts_id=275

if your motor is still rather new hold off trying to lean it out to much and remember no smoke no good you want good consistant smooth power from start to finish