I just got my f4i running after letting it sit for about a year and a half. Idle is perfect, warm up and all. But from idle to about 4k rpms it feels like its running less than 4 cylinders. After 4k it will wrap through the rpms very nicely. Throttle is super twitchy and seems to surge if i am trying to hold speed on the highway. Put new plugs in and put a pc3 on, and it is exactly the same except more power after 4k rpms Even put some fuel injector cleaner in.

I thought it was plugs, but they made little difference. Coil packs maybe?

I know the f4i's are famous for bogging, but surely the bog isn't like this. I am forced to ride the hell out of the clutch so it doesn't stutter when i take off from stop light.

Any help would be greatly appreciated

 

While it was sitting was it tore apart at all? were you working on that bike at all?

 

That brings up another issue.... Bought the bike from a friend who just let it sit. He had traded for it from another friend. This f4i has been owned by like 4 of my friends. At one time they thought the motor was bad, turned out to need a new clutch basket and clutch. One friend pulled a lot of it apart and put it back together ghetto style. So i bought it knowing the status was kind-of sketchy. Ill have to talk to some more of the previous owners to find out what all has been done to it.

 

You ever solve this mate?

 

Not really. Put a power commander on it and have been riding it more and more. Just kinda seemed to clear up lol not really sure how lol