I am working on an older Simplicity tractor. This tractor has a Briggs 289707-0113-01 engine. This is a flat head engine, NOT an OHV.
Last year, I replaced the starter bendix. It has the plastic 16 tooth gear. The bendix is the kind that has a roll-pin holding it in place.
The battery is new and when load tested, tests fully charged and strong. The positive cable was badly worn where it connects to the battery and I installed a new copper connector. The solenoid tests good. All connections are clean and tight.
But after checking all that, the engine still cranks over very slowly. Sometimes it starts but sometimes the cranking stops and I find that the plastic gear on the starter is stuck in the flywheel. I borrowed a known good starter from a different tractor and the temporary starter turns the engine over quickly and strongly, starting the engine right away.
I opened up the original starter and found nothing obviously wrong. Brushes have plenty of life left in them, internal windings are clean, magnets are in good shape.... etc..
So I am wondering, does a starter get weak? If so, from what and can it be fixed?
My customer doesn't mind paying for a new starter but I am having trouble finding a new starter with the same bendix - or doesn't that matter as long as it has 16 teeth?