plug/piston wash is the only way to know, you use someone elses jetting and the porting could be way different, the altitude, air pressure, temperature almost certainly will be, it's bad new. Expensive bad news. Just fork out the $50 and get a decent jetbox going, start WAY fat, and work your way down. If you spend 2 days rejetting 'cause it's burbly rich, who cares really, it's better than squeeking a motor.