early, square oil tank

I rarely see these tanks but a question has come up. The crankcase vent goes to a small tube on top of the oil tank, correct? Then the breather for the oil tank is the little hole leading into the air cleaner. Is this sufficient?

The crankcase breather goes to the rear pipe on top of the tank & the breather tower goes to the air filter or to atmosphere.

Martyn.

seattle##gs said:

The crankcase vent goes to a small tube on top of the oil tank, correct? Then the breather for the oil tank is the little hole leading into the air cleaner.

Click to expand...

Yes, however, there are two types of central oil tank (as it's the central oil tank that has the breather hole directly into the air cleaner).

The early version with the breather spigot attached to the tower (2nd picture in the link, below) and later type with the spigot attached to the top of the tank (1st pic.).

seattle##gs said:

Is this sufficient?

Click to expand...

Avoid overfilling either type of tank especially the early type.

The timed breather off the left crankcase is ineffective at best too, that goes into that spigot on the top of the central oil tank. The breather for the central type oil tank is a pipe that runs from that tower thing down and into the air filter in the front of the oil tank. If you have too much oil, or lots of oil vapor, it goes into the air filter and the drips down onto the top of the gearbox, then down to the bottom of the gearbox, resulting in a lot of oil splash. Of course it keeps things from rusting, but it makes a mess. I tapped that hole in the front of the oil tank to accept a small 'close nipple' to which I attached a hose and ran it out of that chrome cover into a catch bottle. It has resulted in a lot less oil leakage, but at the expense of a lot of work to get the air filter box on and off.

To reiterate, as Les said, there are 2 types of central oil tanks. one with the breather tube off the tower gizmo and one with the breather off the top of the tank near that tower gizmo. They both do the same thing. I think the one with the tube off the tower is the earlier one, if it makes any difference. Mine is the earlier one Apr 69 production date. But I have another of the later version if anyone needs one.

I've always kept my oil in the tank at the lower mark on the cover gauge to reduce vapor and drips.

this one has the tank breather (outgoing) as a small hole that vents into the air filter. Currently it leaves a small dab of oil on the floor after each ride. I told him that wasn't a big deal and to keep the oil level low. I don't believe either made him happy. Another possibility is to weld in a small bung in the top of the oil tank and plug the hole to the air filter.
Someone came by with a central oil tank (alu) for a featherbed project. Made in India. There was no breather fitting either in or out so I had a friend weld in two elbows from the motor breather. They could be turned in any direction and looked of the time period.