i have a '92 cbr 600 f2
'supposedly' has 29k miles on it, just bought it recently (didnt have a speedo/tach unit)
engine is sound, does top end just fine, transmission is good

only thing that bugs me is the rough idle

that sound of the new bikes, fuel injected.. they have a perfectly consistent idle and sounds great. mine on the other hand, is chattery, up and down... idk. just seems like it could be better, but maybe thats just how these things idle.

yes i am aware of the idle adjustment on the side, i have tried different settings.

my carbs are clean, and like i said the bike runs great low-high end.

what could be affecting this? my first guess was the timing. but aparrently theres an idle adjustment in the carbs? could this have anything to do with it?

what are your thoughts

 

carburetor synchronization, clogged pilot jet(s) improper cleaning of the carburetors can all contribute to a fluctuating idle. I recommend pulling the carburetors, cleaning them yourself and then synchronizing.

NEVER trust the word of someone else to say "I just had the carbs cleaned" without paperwork to prove it or actually having SEEN them being cleaned.

 

Yeah first thing I was going to ask is how do you KNOW the carbs are clean unless you have had them off yourself.

A seller will tell you anything to get your money and get rid of their clapped out old bike.

 

because i cleaned them 3 weeks ago

isnt it pretty costly to get it synchronized?

 

ok, I'm going to guess here that you dont have an inline fuel filter do you? I find that many people dont run one, mistakenly thinking the in tank petcock filter is going to do the job just fine, which it does not.

you'll have to remove the carbs, clean them once more, then reinstall, and add an inline fuel filter with a paper media, or porous copper.

not those cheap mesh screened pieces of crap, they're actually less capable of filtration than the petcock filter, so they're pointless compared to porous copper or paper media filters.

 

Syncing isn't that expensive. Buying a tool to do it yourself costs about as much as having a dealership do it once. $80 for a tool. I did it, not sure how much of a difference it makes but it seemed to improve idle.

 

A good carb clean and sync will also improve throttle response and just make the bike perform a hundred times better all around.