Hi, I'm new and confused. I got my 98 cbr 600 F3 about a month ago. When riding theres a slight hesitation under 5k when i open the throttle quikly. It has a D&D aftermarket muffler and a modified airbox and stock airfilter. Do you think the bike needs rejetting or should it already have a jet kit installed and would only require tuning or would it be best to get a power commander??? Thanx...

 

im pretty sure that power commanders are only for fuel injected bikes. you should read up on carbureator tuning, lol. usually with carb bikes, all you have to do is re-jet though.

 

jetting is for carbs...power commanders are for FI bikes

 

Yep, thats right.
If you get it though. They do make an ignition control thing. I cant remember exactly what its called but it looks just like a power commander with a different name on it that is for carbed bikes. It doesnt mess with fuel though. Just the spark.

 

If you already have a jet kit installed, then it sounds like you need to lower the jet needle clips one position. This will raise the needle up which makes it open quicker which allows more fuel to enter the combustion chamber under acceleration.