1940 BSA M20 rides again


Dec 9, 2008
After about a 2 year restoration, the 1940 Beezer is rolling again. This 74 year old side valve machine has had significant work done on it including a complete engine rebuild with new barrel liner, piston & rings, new conrod and new big end. Plus the gearbox has been fully rebuilt, the Lucas magneto has been refurbished, a new Amal pre-monobloc carburettor fitted, wheels have new rims and spokes and forks rebuilt with new head bearings.
Starting and riding is..... different.
There is no ignition switch and it goes like this; Free clutch plates using kickstart. Turn on fuel. Tickle carburettor till fuel leaks out. Turn engine over with kickstart to compression. Pull in the decompressor on the left side of the handlebar and turn engine just past TDC. Set the manual timing lever on the right side handlebar to full retard. Give a full follow through kick...... and with luck, she should start.......
The slow tickover sounds a bit like a ships engine. When riding, need to move the manual timing lever depending on the riding conditions, retarded for long hills or stopped at traffic lights and advanced for high revs and normal riding.
Another real classic bike back on the road, fantastic.


Ian Bungy

Sep 19, 2006
Great Job Ian. Fantastic Work. The Older Bikes were a lot more complicated than the New Push Start Button and Go era! Sounds a bit like the Old Royal Enfield's! Very slow tick over!