Questions? Looking for parts? Parts for sale? or just for a chat,

The WD Motorcycle forum

WD Motorcycle forum
Start a New Topic 
Author
Comment
BSA WM20 crankshaft play?

Hi,

I want to ask what the axial play on the crankshaft should be. Measured after mounting the crankshaft in the engine block. I measured 1.5 mm, I have to use washers to define. But what is the maximum allowed size?
I read somewhere that the maximum clearance is 0.25mm.

Many thanks
Marcel

email (option): bennito@centrum.sk

Re: BSA WM20 crankshaft play?

Axial movement of the crank shaft within the cases isn't strictly a factor with the M20 and isn't something to be concerned about...Any axial play is taken up when the engine shock absorber nut is tightened up and the crank is pulled up against the drive side bearing..All play is then removed and the crank is fixed in position....

The position of the crank within he crank case, after tightening up the shock absorber, is a factor though...The con rod should lie centrally to the crank case joint after everything is tightened...To help achieve this the spacer between the two drive side bearings should be within tolerance (1.000"-1.005" long) and the crankshaft oil flinger plate should be fitted, unworn and flat where it sits against the flywheel and the bearing inner race...Ian

email (option): ian@wright52.plus.com

Re: BSA WM20 crankshaft play?

Of course. I forgot about the muffler. Thank you IAN for the comprehensive answer.
Today I will put it together as a whole and measure the axis of the connecting rod.

Perfection Ian.

Many thanks

Marcel

email (option): bennito@centrum.sk

Nieuwe pagina 1