Cam someone help me, i've bought a bsa m20 in bit, got most of it sorted now.. apart from the oil take of pipe on the left side of the crankcase, just below the barrel, what does this do, is it a vent, or does it return to the oil tank, if so how does it fit on the oil tank..? Thanks anyone..
Hi Doug...That is the crankcase breather pipe and it vents to atmosphere...It goes down behind the inner primary chain cover where it is clipped to the gearbox mounting plate using a p clamp and nut/bolt...
The fittings that screw into the crankcase, to which the pipe attaches, contain the breather valve which is a flat tufnol plate that is move back and forth under crankcase pressure and vacuum as the piston rises and falls....Ian