oil leaks

hi Andrew
I usually run about 20 drops per minute through but it depends on the engine.i would sooner put too much through than too little.Would sooner decoke than fit a new crank or piston or both.It is like you say the better the vacuum then more goes through.
as regards the gearbox leak,i also have a gearbox leak an I will be putting it on the bench in the next few weeks so will post my finding but basically when I rebuilt the engine several years ago I put gasket compound on the brass plate between the gearbox and diff. it was fine. Then I had a knock on the clutch and stripped the engine out but did not reglue and it has leaked ever since so I hope that is the problem ?

I have being riding a lot of "total loss" motorcycles, 20 drops a minute is fine some more uphill, not sure wich vacuum we are talking about but the crankcase breather has to have a valve, blowing out but not sucking in will keep the oil in.
I am riding "Shell Corena S2P" becouse it will reduse decoking.

hi the abc has two one way valves fitted.one to let the oil in and the other in reverse to let the mist out,does it need one on the inlet? I don't know. While on the subject if you put jointing compound on the crankcase halfs be very careful because the inlet splits just inside the crank.There is a drilling that takes oil to the front half of the crank and you can block the drilling up when putting the cranks together.
The oil you use looks interseting

hi again
I think I missed a piece out yesterday Most abcs don't have an oil pump fitted I think the prototype had them fitted then they had to cut costs and the pump was taken off.probably the biggest mistake they made. So the pistons go to the top of the stoke and a vacuum is created which then pulls the oil in and on the upstroke stroke it send the mist out through the other one way valve