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buy a small high efficiency, like 1.5" x 1.5" 12vdc pump that can handle oil, (Amazon 15.00) Then connect to crankcase vent line and pump back into oil tank or connect to oil tank vent line. Oil tank is not a pressure vessel. Good Grief whoever said that.
make sure pump is on a keyed power wire.
ive had a 1991 FXRSSP for years.....this will fix it permanently, park it for winter even, excess oil will return to tank.
If yer nervous about oil going wrong way, don't, pump acts as it own check valve.
Alf ...FXRSSP......FLTRI with sidecar......FLHTC...'....64 Servicar Chopper w / the old TA radials and Cragars and 11" over girder springers. Disability Scooter
"The HAMMER" Stroker and Ninja Killer Yes, used to be a Road SMASHED FXRS-SP Now s&s bank robber...."Broke Veteran" HA!!!
If I read the OP correctly, he wants to vent at the oil filler cap. In my humble, non engineering opinion, crank case pressure will vent through the easiest path. The umbrella valves will become irrelevant and the blow by and oil mist will vent out the cap moving the mess from the air filter to whatever is behind the oil fill cap. Harley, or an owner could just as easily connect the vent tubes to the intake manifold rather that to the air cleaner and change the circuit flow. That would eliminate the air filter mess but would still run the oil mist back into the engine with the associated deposit build up in the combustion chambers.
Great way to do this no mess
