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How do you stop a BSA M20, 44 frame, 51 engine

Hi,
How do I stop the engine running without turning off the fuel or stalling it. My Ariel has a kill switch on the magneto but I can't find anything on my BSA? any help gratefully received.

email (option): kli24532@hotmail.com

Re: How do you stop a BSA M20, 44 frame, 51 engine

Ken
If the carby doesn't have an air filter you can place your hand over the bellmouth, depriving the engine of air.
But it should have a valve lifter, indicated by a small lever below the barrel on the front right hand side of the crankcase, connected to a smallish control lever probably on the handlebars. Pulling on the lever raises the exhaust valve off its seat destroying compression. This makes the engine easier to turn over when starting & in your case the lack of compression stops it running.

Re: How do you stop a BSA M20, 44 frame, 51 engine

Thank you, I thought that may be the case but wasn't sure if something was missing. The wiring was a real mess.

email (option): kli24532@hotmail.com

Re: How do you stop a BSA M20, 44 frame, 51 engine

Ken
The lever I mentioned is of course at the base of the cylinder barrel, adjacent to the valve chest.
One should always have 2 coffees before committing ones's thoughts to print in the morning.
Taking the cover plate off, you'll see how the lever & tappet engage. Make sure there's clearance here at all times.
Good luck with the wiring. Others would know better but I don't think any M20/21s of that period had ignition cutouts, needless complexity on such a utilitarian machine. But it means that apart from the high tension you don't need any wiring at all to make it go.

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