Joe and grumpy,
I've checked the starter and it is fine no damage no movement nothing, looks fine.
when it did start it wanted to run flat out so definitely put excess pressure on the key.
I'm going nail it down and say that I have not nipped up the flywheel adequately, as I could have tightened it up further. With the repeated shearing play has built up exponentially and every time it has made the tapper worse and more damage, worse fit, blah blah.
Ok, I have a spare crank and matching flywheel but the pto end is incorrect for the mower so will be a good crank to test the engine, get the other crank mended try again.
