Motorcycle Repair: Not running right after Air Filter Change..., vacuum leak, air leaks

Question
We put a aftermarket round air filter on my wifes '85 Honda Rebel. Took off air box for cleaner look. But know her bike will not idel right. Tried jetting but with no luck. It ides fine with a 38 round jet main, but runs rich in 2/3 to wide open. Will not go past 35 without bogging out. Tried lowering main jet to 122 from 128 but made idle rough. Does anyone know what a good combo if if you out on a different air filter?

Answer
Jason,

-when you change only the air filter the most
you need to do is go up one size on the idle,
pilot or low speed jet.

-Don't change the main jet from standard.
The engine will only need a main jet change
if you changed the air and exhaust systems.

-standard low speed jet should be around #35 and high speed
or main jet around #135.

-check the spark plug color after a run,
turn it off quickly. If the plugs are black
you are getting too much fuel or not enough air.

-is it possible the jets are in the wrong way
or you have an air or vacuum leak around
the carb somewhere?

-a new air filter should not make the bike
run rich, if it is running rich you have a jetting or
other problem happening. Probably jets are too large.

-the main jet only affects running at 3/4-full throttle.
if your idle is off, it will be air leaks or
wrong idle jet. If your high speed is off it
will be main jet or some other problem with carb,
plugs or ignition.