I just bought an 09 Fatboy and everytime I start it, I hear this loud knocking noise?? It is just one loud knock and then the bike starts. Is this something to be concerned about? I moved up in the world and went from a Sportster to this Fatboy so I don't know if this is normal or not?

 

I believe it is the compensator in the primary and more than likely is the normal rap. Compensator is designed to take pulses out of drive line for a smoother ride, I believe. Others could probably expand on the subject. I think all of our scoots make this noise when first cranking.

 

Well I guess that answers that. Was wondering if they changed them in 09s. Same comp as the 07s, which is the source of the noise at startup.
Ron

 

Thanks guys! I had myself worried for a second.

 

I read about it somewhere. The slap is normal at start on these motors.

 

normal, if it didn't I would worry