I have a very relaible 1950 A10 Rigid, built up by Matthew and Margaret Mason, of Gannet Racing fame in the 1980s.
Earlier today (after a long/fast run) the bike started to suddenly backfire at high revs.
It is fine at low revs and ticks over like a clock.
I suspected ATU and was surprised to find there is no such device under the timing cover! (Only the magneto pinion, bolting onto the K2F magneto.) This is the first time I have ever had need to take this cover off, as the bike has been wonderfully reliable for over 30 years. It has never had a manual advance/retard.
Can anyone explain what is going on and how can i sort the backfire issue please?
Recently, the points were changed, but the timing/magneto/slipring have not been touched.
Also, can anyone put me in touch with Matthew or Margaret Mason? My mate was a customer of theirs in their Didcot Shop 'Masons', and he ordered the bike from them in the 1980s. I bought the bike off my mate 20 years later, after he stopped riding, following an accident.
Many thanks Neil