1970 Ironhead, Oil coming from breather pipe?

[Blue Collar Moto]

Hahaha! I just looked at google for ATF. this is one of the things I got besides the cops. "Asian Tennis Federation"
Ya, just beat it with a tennis racket. That I'll do the trick! Sorry.

[acox]

Hi,

I was riding in the summer and I did find that the leaking was ok during that time . Until I filled the oil tank up . And then it managed to start leaking and leaving a trail behind me again. And after doing winter repairs and modifications (Completely moving the battery, oil tank, rewiring all electrics, new jockey shift and pedals....was a few things wrong with my first attempt and metal work impriving every time! ), I restarted a few days ago...and leaking again...alot.

Did some investigatoin and the oil tank has two oil lines coming in near the top where you flil the tank. And then the oil passes through the filter into the tank, where the feed exits tank to go to the oil pump. The two top oil pipes /lines will be the return and I think the Cam Chest Vent.

I found this really really nice oil line sketch here: http://www.sportster.org/tech/misc-ironhead/oil-route.shtml. I just realised that in this diagram the cam chest vent is in the tank after the oil has gone through the filter if I read the diagram correctly (ie a low pressure area in coamparison to where the return feeds into the filter. This made me think my problem is that the oil return pumps and as there as so much pressure pushing oil through the filter...then oil is probably also being pumped back through the cam chest vent. This would cause excessive oil in the engine (Similar effect to the excess oil at startup if the check ball valve allows oil to leak whilst standing) and then the crankcase breather spit out oil.

Does any one know if:
-Oil can go back into the engine like this through the cam chest vent?
-In most oil tanks is the cam chest vent after hte oil filter to prevent this?

Any information or help would be appreciated.
-Andy.