Ok guys im in need of some help please... My sons 2003 piaggio nrg mc3 lc siezed up on him the last week after the piston rings snapped. So i removed the engine and replaced the barrel, head, piston / rings, small end bearing ect. Whilst i was at it i decided to have a look inside the crank case to see if any parts of the piston rings had gone inside and it was clean as a whistle. Since putting the bike back together it is having a problem going past 900rpm's, it will shoot off like a rocket from stand still and then get to 900rpm's and then drop down to 600rpm's and the creep up slowly to 35mph and stays there. The bike has a polini race veriator with 7g rollers, a gianeli race pipe & 63 main jet. the carb has been setup corectly 2 1/2 turns for mix screw & 3 turns on idle screw, but it just wont go any better. Can it be the belt or the rollers may be to heavy??? any advice would be great THANK YOU.
