I have just rebuilt the carbs on my 99 GP1200x (non-pv), one issue is solved (porpoising and lost speed) but replaced with another. Now, ocassionally it will not rev beyond 2K RPM (7 mph). When it is mis-behaving in this manner, the engine is making a cyclic sounding tone. When not mis-behaving like this, it boggs down when given the gas, then picks up. It sometimes starts to mis-behave, then suddenly picks up and runs normally (50mph). Any suggestions?