I have 99 Sport 400 and I have rebuilt everything on this thing new cables, fixed brakes, top end rebuild - bored out .40 over, rebuilt carb, rebuilt both clutches. I have purchased a used carb and tried it but still this thing bogs down when accelerating. It will rev up fine on the first push of the throttle but anytime you try to rev it up it falls on it's face. I have tried smaller main jets, raising and lowering the needle. When you hold the brake and nail the throttle it will just about jerk your head off then fall on it's face. It idles perfect and when it revs up the first time you hit the throttle it sounds fantastic.

Any ideas for this Polaris?

 

How long has it sat?? Check exhaust for dirt dobber nest if it has sat very long. Happened to me

 

I have looked into that a little bit, but from what I can tell there is no clog but all I have done is unhook the exhaust from the header pipe and ran it but that was before I rebuilt the carb. I will check that again and see if bogging down problem goes away when the exhaust is unhooked.

Thanks

 

I checked it last night and it does look like the exhaust is clogged. Any idea on how to unclog the exhaust. it is not clogged close to the end of the pipe. Should I take a wire and run through it???


Thanks for the help