BSA Sloper Kickstart Pinion Repair

Sloper kickstart pinions have a hard life. If the kickstart is ‘jabbed’ rather than engaged and then swung, the first couple of teeth take the full load of a heavy crankshaft, the engine’s compression and, back in the day, winter engine oil with the viscosity of treacle. Not surprisingly, ninety years later, they are usually in a sorry state. Mine was no exception. An old dodge was to grind the damaged teeth away – but this reduces the effective swing of the kickstart lever, making starting harder still.

Specialist welding looked like a way forward and after a discussion with Richard Kimberley, I sent the pinion off to him to repair. The damaged teeth were built up with weld and a template for their form created from an undamaged area of the pinion. The restored area was then quench hardened to resist wear, and the result looks like this –

As I mentioned above, kickstart pinions are often damaged. I bought a complete Sloper gearbox in the hope that it would provide a decent spare – but while the rest of the gearbox was in excellent condition, the kickstart pinion had already been the subject of an interesting repair! Still, at least I’ve got a spare …