1965 Big Ten starter/ generator hums

[thirdjoker 0]

I mowed with this about a week ago. It has been running like a top since I've had it. ( kept in a dry shed) I went out last night to start it and the starter/gen just hums. It will not turn over. I checked for voltage 12.97v. I turned the starter and motor by hand- both are free spinning. What are the troubleshooting steps I need to do?

[BLT 718]

You can do this test with unt mounted to insure unit is sound. If it passes those then look for dirty connections including the starter button contacts.

[thirdjoker 0]

Thanks Bowhunt - even though it didn't turn out to be the cause- I still learned something by doing what you suggested. +++++just a follow up. I checked all my wiring for continuity ( I had rewired it ) good. Checked for voltage- good. I had a old battery on the shelf- swapped it out. started right up - 1st crank. That led me to the battery. I had purchased this Optima yellow top about 3 months ago. It read voltage .put it on the charger. still will not crank. I'm taking it back to have them test it -

[theniteowl 29]

You can have a battery reading correct voltage but still not able to provide the amps. They will have to load test it at the shop.

Good news for the S/G though.