Venting the oil tank

[crock]

Every once in a while the old girl will spit out the oil tank cork. I've talked to a few guys about it and their answer collectively is "HUH". I have checked the crankcase vent line and the line to the top of the tank that is supposed to vent the tank for obstructions and every thing is clear and open. My though (Because I"m tired of buying oil tank corks) is maybe install a "T" in the line going from the case to the top of the tank. What do you guys think?

[SP33DY]

Maybe it's time to do a cylinder leak down check.

[JSD]

What year bike as early tanks had a update to filter canister they drilled a vent hole for that reason. Shown in early manuals or Donny Petersons shovel book. 

[76shuvlinoff]

Mine will do that after sitting all winter and doing a little sumping.

[crock]

What year bike as early tanks had a update to filter canister they drilled a vent hole for that reason. Shown in early manuals or Donny Petersons shovel book.

It's a 1973. I run a perform filter so there is no canister. It never did it in stock form. The motor is a 98 inch with about 8000 miles on it built about 6 or 7 years ago.

[JSD]

Restriction in vent motor to tank . The oil tank is being pressurised. The vent equalisers the 2 . The old manuals says the camel hair filter wold block and cause same problem. Have you tried a new performo filter ?

[bump]

Do you have the vent hoses connected together? One runs from above the oil pump to the oil tank, the other runs from low on case and dumps on ground or catch can. That is where the oil comes from after sumping.

[crock]

Restriction in vent motor to tank . The oil tank is being pressurised. The vent equalisers the 2 . The old manuals says the camel hair filter wold block and cause same problem. Have you tried a new performo filter ?

Do you have the vent hoses connected together? One runs from above the oil pump to the oil tank, the other runs from low on case and dumps on ground or catch can. That is where the oil comes from after sumping.

Already been running the Perform filter
No' the hoses are not connected together. They are run by the book(Checked and double checked). As I said the motor has about 8000 miles on a bore and stroke but has just started doing this last fall. I spoke to the builder and he scratched his head and said "huh".

[JSD]

Is it using oil ? Burning low oil in tank using. Compression test. Plastic breather gear ?