Last season I replaced the ring gear on my flywheel whilst I was sorting out what I thought was a bigger issue with a stub shaft. Something as ‘simple’ as replacing the ring gear turned into ruining one ring gear and then having to have the flywheel machined to accept a standard 110 tooth replacement one. At the time I thought it would make sense to also replace the starter motor as the teeth, like the old ring gear, were pretty worn to my eyes.

I opted for the starter sold by Sheridans and marketed as the replacement for a pre-crossflow engine along with some qualifying copy that only their starters would fit as the bell housing on a Watermotor is different from the automotive bell housing.

It was notable the the bendix on the new Sheridan’s starter wasn’t super-smooth but this would probably loosen up with a bit of use.

With everything fitted back together, although the starter would mesh with the flywheel, it only really did so half the time. The other times it would either ‘ping’ off the flywheel, grind slightly or not throw out. I put this down to the starter being new but after a summer season, the poor meshing continued.

At this point, for the sake of £130 I decided to source another starter with the aim of finding a different manufacturer. I discovered that Boulters Chandlery in Wroxham listed and stocked two different starters. The key difference was some minor dimensions but the main one was number of teeth on the bendix. Sheridans didn’t offer more than one option and didn’t specify the number of teeth.

It turns out that the bendix should either have 9 teeth or 10 teeth and that although 9 teeth is considered standard on an older pre-crossflow engine, 10 teeth isn’t ‘wrong’ as such. A 10 tooth bendix would spin the flywheel a shade slower but gives more torque.

On removing the Sheridan’s starter it had 9 teeth, the replacement had 10 teeth.

Taking the starter out and re-fitting requires the nuts being accessed from the front of the engine with long extensions to a socket wrench. Removing the oil filter makes life a lot easier and at this point I was very pleased to have upgraded to a spin-on filter making removal and access a lot easier. On removing the Sheridan’s starter and comparing it with the Boulters replacement, the Boulters one had 10 teeth.

With everything put back together, the flywheel and starter meshed perfectly and span up with no nasty noises or fuss. I’m still on edge expecting a ping or a grinding, but all seems well.