Hello all. I've been given my first bsa for a light rebuild, the owner said it's taken 40 years to look like that and that's how I want to keep it!
Anyway, an engine is an engine to me, but I have some questions about the ignition system. I have spark at the dynamo but am unsure how to set the ignition timing? Also as there no key and the dynamo generates it's own spark once the engine is turning how do you stall the engine when you finish riding?
First of all you need to understand the electrics of your bike. The bike is fitted with a dynamo at the front of the engine this is there for the sole purpose of generating the electrics to power the lights only. At the rear of the engine is the magneto the sole purpose of this component is to generate the spark to fire the plugs. There is no key for the ignition as magneto ignitions do not require one, to stop the engine there should be a push button fitted on the handlebars which when pressed will stop the spark from going to the plugs thus stopping the engine. As for ignition timing I would suggest that you purchase workshop manual and also a parts manual because at some point you are going to need both, these can be purchased on line at reasonable cost. Setting the timing entails taking off the timing case loosening the auto advance and retard off it's taper then setting the piston at he correct position then fitting back the auto retard mechanism in it's fully advanced position with the points just breaking open. I would suggest that before attempting this you read up on the proceedure fully. You could go to the following website www.a7a10.net where you will find all the information you require just type in the search section for what you want.