I have a 2008 ltz400 . just bought a brand new jet kit with a 165 main jet and 22.5 pilot(stock)I have a fmf powerbomb pipe and a hmf silencer. With stock air box. It is not getting full power or barely any power at 1/2 throttle to WOT it just cracks and pops. Do I need to put in a 180 main jet or a new throttle positioning sensor.