This was my dad's tractor so I don't know a lot about it except that it is about 4 years old. I went to start it and the B&S engine barely turns over. It makes a buzzing sound and if it was a car, I would suspect it to be a starter motor or bendix gear but I don't know enough about lawn tractors to know if they even have such parts. I checked the battery and it has a full charge. Where would a starter motor or bendix gear be on this type of tractor.

There should be a positive (red) cable running to a canister on the side of the engine. That would be the starter with the little bendix gear that engages the ring gear on the motor.

Your on the right track. Before suspecting the starter, try jumping the tractor and/or getting the battery tested. Only a load test will confirm battery health as good.

There are lots of ways to determine if a battery is bad, but only one real way to determine if it's good.

Was right on.

K.I.S.S. was right on. I jump started the tractor with no problem at all. A new battery is in my tractor's future for next season as this one will not hold a charge.

Dave, be sure to use a new battery with at least 300 cca.