hey guys i was reading through my new jet kit notes and it says something about if you rev the bike and it doesn't come back down to idle right away there could be a vacuum leak. my bike is doin this. has anyone else experienced this? is there a common spot to check first before i dive in? the motor does have over 50,000 on it but i was hopin it wouldn't need a major overhaul anytime soon. thanks for any help you guys can throw out there.

 

How long does it take to come down?

The CBR by nature have a heavy flywheel and the revs dont drop that quick.

 

it comes down after acceleration okay but before it gets to idle speed it hesitates for a bit so i don't think its just the weight of the flywheel

 

Are all rubber caps for vacuumtests in place ?

 

How often does your throttle get stuck? Mine did not roll back all th way!!! did the same thing!!

 

i dont think the throttle is sticking, it seems very quick to snap back into place. the rubber caps are all installed also. i wonder if the rubber intake boots the carbs attach too have gotten hard and crusty and are letting air past?

 

You could do a leak-by test: spray some WD-40 around the intake boots. If the revs increase, there's your leak.

 

Are you sure you just haven't got the cables mis-adjusted.

 

To the OP, if the idle doesn't return to normal smooth idle quickly it's too rich. If it returns and then stumbles before resuming normal idle it's too lean. This only applies to the idle cuircit however. If the needles are bad or the jets are wrong that only effects off idle performance.

 

yeah i've got the cables set up correctly, i'll have to try the wd 40 trick.