Lucas NC1 manual??

[FerG3]

Another suggestion re root cause of oiling maggy is crankcase breather. Where do I start with that one?

[dave16mct]

At the breather, underneath, behind the chaincase. If you can get it running you should feel air puffing out of the pipe to the beat of the piston. The pipe should be short, pointing down towards the floor.
Dave.

[FerG3]

Thanks, Dave - sorry, I meant what are the causes of poor crankcase breathing - just blockage of the breather? Presumably crankcase pressure can increase with wet sumping?

[dave16mct]

Usually stuck crankcase breather flap valve or worn cylinder bore and rings. Sometimes a longer pipe is fitted from the breather and looped up to connect with the oil tank breather pipe- not a good idea, oil will just fill the loop and stay there blocking it.
Dave.