classic motorcycle forum

My 1932 BSA W32-6 500cc side valve will not start when the engine is hot. It will start when cold with just one kick and run beautifully, however if I stop the engine and attempt to restart it when it is hot it will not start.

I had this problem in 2017, which I solve by having the magneto rebuilt. I’ve done approximately 800 miles since the magneto was rebuilt by Tony Cooper (I believe he is now retired).

Could the magneto have failed again with such little use or should I look for other issues. I would be grateful to hear your kind advice and details about how to diagnose this and correct issue.

I recall when we were kids ,a friend in the next street had one of these .........he couldnt get it going ,ever .......we used to go to his place get the bike going ,race around the streets on his fathers mower petrol until it ran out ..........there was a school and a church across from his house ,and these people didnt appreciate speedway riding in their grounds. ...........I had a terrific crash on it and tore the inside out of my knee.

and

Thanks folks.  This bike is proving to be full of "creativity".
A modern one is already on order.

Not only does it look like a rectifier, you can actually see the 4 individual diodes
that make up the diode bridge.

And potentially replace one if it goes bad.
Dunno about that R1 .....

https://cdn1.byjus.com/wp-content/uploads/2023/03/Bridge-Rectifier-1.png