Motorcycle Repair: carb problem, honda ct70, air leaks

Question
81 Honda CT70- when i rev this bike up the rpm's stay high for a few seconds then drops back down to idle. with the choke on the bike runs good and doesn't stay revved up when the throttle is released. seems to be running hot.has a little bit of an occasional sputter form exhaust. thanks for your help!

Answer
Gary,

sounds like a lack of fuel or an air leak
on your intake or carb.
-Check the throttle cable and carb slide
to make sure nothing is sticking.
-Check intake flange and rubber connections
for cracks or air leaks, try some
carb cleaner around them and see if the
engine speed changes.
-You might want to check the points condition
and clean them, set ignition timing
so points open when the "F" mark aligns
on the flywheel/rotor.
-Make sure the carb is clean and has fuel
getting to it ok from the gas tank valve.
-Check valve clearance when engine is on
compression and "T" mark aligned on rotor.
.002-.004" clearance. Make sure valves have
some clearance.
Air leaks or ignition timing off can cause
overheating. There may be an ignition advance
cam on flywheel sticking, but rarely.
Make sure air filter is not plugged.