I have a 2002 honda cbr 600 f4i with a power commander, yoshimura rs-3 pipe, k&n air filter, manual cam chain tensioner. Ok here is what is going on and what i have noticed. When i start the bike its starts fine but when you open the throttle wide open from idle it bogs and stutters untill its gets above 3k and then i takes off smooth till red line. It is the worst when the bike is cold and then it gets about 20% better after it warms up. It dose it in gear and also just as bad when the bike is parked in neutral. I have tried to lean and richin the power commander and there is no change. I run 91 octane. I have tried a fuel system cleaner which did not help. I know there is not a lot of power on the low end but i think it should wrap out smooth when it is in neutral. Once your above 3k the bike is fast and smooth all the way up to red line. Are they any sensors i need to check or adjustments i can make to fix this problem? Thanks

 

Fuel regulator valve..



How to replace it: LINKY HERE

 

Just ordered a fuel pressure regulator i should have it by the middle of next week. I will let you know how it runs after i put it on. Thanks

 

You could also run fresh fuel mixed with Seafoam. To clear out possible residue in fuel injectors

 

Hi, I also have an F4i, 2002 and I have the same problem. But I also notice stuttering and very unsmooth riding when in the 3-4.5k rpm band when the bike has warmed up in hot weather. On the freeway its fine, but when i start getting in city, and lots of stop and go, the bike seems to run on 2 cylinders. Its horrible.

I have recently put in Denso Iridium plugs, did a Full Synthetic Oil Change a couple months ago with Castrol Bike Oil. I clean and lube the chain, and use Shell 91 Octane fuel. would changing out the Fuel Regulator valve fix this symptoms too?

 

Hi y'all this is my 1st post . I have a 2002 f4i with only 4k on it and it Boggs the warmer it gets . The idle drops down but wont shut off.