I would start by checking that the starter ring gear has usable teeth all the way round. Motors tend not to stop in a random position, so it's not unusual to get one or two places on the ring gear which are very badly worn while the rest of the ring gear is OK.

To check the ring gear, just remove the starter motor and slowly turn over the motor from the flywheel rim with the spark plugs removed.

Location: N W Kent

Thanks for heads up!



If it is the ring grear is it a big job to swap?

Best

Pete

On your car, the ring gear is an integral part of the clutch cover plate, so you'd either need to find a better one and swap it. Or alternatively, build up the worn teeth on the one you have with weld and file them to shape. Unlike "proper" gears, the tooth form on the ring gear isn't super complex, so this job is quite do-able without machining, just takes a bit of time and patience.

Location: N W Kent

New ring gears are available from A7 suppliers and can be fitted by machine shop.

Or re-bolt the clutch pressure plate 90 degrees around and place the undamaged teeth in the usual stopping place

Tony.

Location: Malvern, Victoria, Australia.

If only it was that simple with worn teeth on the later flywheel. Intersting to read that you can build up the teeth with weld. Just a month too late for my flywheel. An old article in impractical mechanic magazine (or some such publication) suggested drilling and tapping to insert bolts, then filing them to shape. Didn't fancy that much! I went for a flywheel with a new ring gear and an hour of lapping to remove the wobble.

Does anyone have experience of the longevity of the welded denture approach?

Regards
Nick

Wouldn't have suggested it if I hadn't actually done it

I restored my '31 tourer in '79-80 and along with my '32 Special, it was my daily driver till 1987. So the welded tooth repair on its clutch cover ring gear lasted that long without any problems.

To check the tooth form as I was filing the "new" teeth to shape I made up a sort of comb device that had a number of teeth in negative, this was traced off a a good section of the ring gear and used to compare shape/height as I worked.

Location: N W Kent