The plea below for help was posted on another forum, but has had no replies. Thought I'd try to help the bloke by posting it here. I'll pass on any suggestions.
"My bike will not start. Please read all my post before responding
After having difficulty starting my BSA W32-6 4.99 hp side valve (1932) when it was hot I had the magneto professionally rebuilt. I was also advised by Tony Cooper who rebuilt the magneto that it would be more reliable to replace the original Lucas
three brush dynamo with a later Lucas
two brush dynamo; so I did. Hence I have a Lucas
MS1 magdyno fitted, with a later Lucas
Tony also advised me to replace the mechanical regulator, which was a coil on the back of the control panel switch (Control switch setting are off, charge, High beam and low beam). He told me it would be better if I replaced it with a Teb-tec solid state encapsulated regulator. Again I have done this.
When I replaced the magdyno I removed the cylinder head so that I could see that it was at Top Dead Centre, when the piston was at the top and both inlet and outlet valves where closed. I then located the magdyno into the sprocket with the ignition in fully retarded position. This is the method stated in the BSA Motor Cycle Instruction Book (All models 1930 to 1936 inclusive). The exact wording for all 1932 BSA motorcycle is:
Piston at T.D.C Ignition fully retarded, Contact Breaker points open .003”
Before locating the magdyno into the sprocket I had rotated the contact breaker assembly until a cigarette paper could just move between the points and left it where the cigarette paper just comes loose. I made sure that it was fully retarded by not connecting the cable to the leaver, hence the cable was loose.
Both the inlet and outlet valve (Tappet) clearances are correct, .004” inlet and .006” exhaust.
When I attempt to start the motorcycle it will not fire at all. I tired starting the bike fully advance, half advance and fully retarded; however the outcome was always the same it would not fire at all. So I did the usual check for air fuel mixture and spark at the spark plug. I removed the spark plug placed it against the engine and yes there was a spark, also fuel was gently dripping out of the carburettor which indicates that the fuel was getting through.
Then I tried spraying Easy Start down the carburetter mixing chamber, again I tried bike fully advance, half advance and fully retarded. It would only back fire sending the force back through the kick start.
My question is how do I diagnose and remedy this problem.
Thank you for your kind help"