my bike acts the same...intermittantly. i dont ****ing understand it. i got a new fuel filter, problem went away for a week...then came back. i dont understand! whats a solenoid?

 

A solenoid is basically just an electronically controlled vent. It has 2 inlet sources and 1 outlet. In our case it has one inlet from the front vent tubes and one from the ram air duct. the outlet is to the carbs. from 0-12 mph the solenoid feeds the carbs through the front vents, from 12mph-top speed it switched the feed to come from the ram air duct. If the solenoid becomes dirty or the electrical circuit fails it will attempt to feed the carbs from the small front vents which will result it a vacuum in the bowls- this will force a lean condition and bog the engine down.

 

Oh I should add that if its acting up intermittently It could be a sticking solenoid or loose/ corroded connection. I would start with the bypass and work from there. Its a common f3 problem.