I have just bought a 1967 B40 ex WD..and I'm pretty new to British bikes.
I am sure this has been covered before on the site but I'm going to ask anyway.
My bike leaks oil a lot and it's not the engine oil as it stays at the right level.
I'm thinking gearbox.
So is it a matter of fitting new gaskets to the gearbox side and primary side.
Or would there be something else causing the loss of oil.
Is it straightforward enough for someone new like me.
Thanks in advance.
Borderlord
Is there any indication where the leak is at all? Does it leak more when running or is it the same running and standing? If you can't see any obvious leak then clean the bottom of the engine as best you can and then try taping suitable pieces of kitchen paper towel to the various areas (along chain case, bottom of gear box, bottom of timing case) to see which one gets the oil drips first. That should give you a better indication of the problem area.
is it always a matter of a new gasket? Well, it can certainly be that. But sometimes it is a scored mating surface or excess engine pressure and a number of other possibilities. Fitting gaskets is not a hard task. It might take a bit of "mental mechanical orientation" but it is technically not difficult. It helps to revise the procedure with the factory service manual. It will tell you the steps you need to take to do any particular task. Gasket changes are usually quick and simple, at least on the chain case side. If the mating surface is damaged or heavily scored then some more remedial action might be needed. The problem can often be solved with some silicon or other sealant made for the job.
If not the gaskets then some of the oil seals might need replacing. That is more demanding but quite within the remit of the amateur mechanic. The factory manual and YouTube will help at lot. if you do have to disassemble anything for more than a short while then somewhere to do it and to layout the disassembled bits is an important consideration. It can help to take photos as you go.
But the first step is to locate the place(s) the oil is leaking from. Good luck! :0)