I bought a used 2000 CBR f4 a few weeks ago and finally got around to cleaning the carbs out today. Immediately after I cleaned them and got the bike back together it felt like it was running right. But after riding around for a bit I noticed it backfiring and just feeling sluggish. I can also tell a difference in the sound of the exhaust pipe from before vs. after. It sounds deeper and a bit fuller, but with more popping noises. I'm thinking that maybe the air/fuel mixture is wrong. Does that sound right to anyone? And if so, how can I change the ratio?

 

I had the same problem with mine. It was caused by dry foul on the spark plugs. Check them.

 

Hey thanks for the suggestion, now I just need to know what a dry foul is... What should I check for to see if that's the problem? And how do I go about fixing it?

 

Basiclly if your plugs are discolored and look like they have soot.

 

Alright I took em out and checked them and they look a little dark and kinnnddd of sooty. But compared to a car spark plug they're pretty normal I think. But anyway, to fix this particular problem should I just replace the plugs? Or is it running too rich/lean? What do you think?

 

Whats a little dark? Get some electrical cleaner, clean them and put them back in.