Motorcycle Repair: harley trans vent leaking, tranny oil, dipstick

Question
have transmission fluid leaking out of vent on 2000 flht it only leaks after bike has reached 4000 rpm doesnt matter if setting still in neutral or if you are riding it can give more details if needed ps already replaced vent and new one is free and working

Answer
The only transmission "vent" is the upside-down J-hose on the top left side of your transmission. The only reason for that to "leak" is if the transmission is overfilled.  Drain your tranny oil (5/8 hex plug on right side underneath tranny) and add only 20 oz.  Maximum is 24 oz. and there's always a couple oz. left clinging to every thing.  Tranny will shift a little easier too.  Trans oil is checked on the dipstick with the bike STANDING STRAIGHT UP, NOT ON THE SIDESTAND.!!!  If you checked/filled it to top line on the dipstick while on the sidestand, it will be about 8 oz overfilled and will blow out the breather hose.  People do this all the time.