Yes by all means try spinning the motor blades by hand, and see what gives there.. I would also ohm the coil with it disconnected and see what is going on there. I am assuming you don't feel comfortable putting in your own receptacle outside? If you don't feel comfortable then don't do it.. but if you do, you could save some bucks there, by getting your own rain-tite box and crows foot receptacle for it. You are going to want it sooner or later. I put in 50 amp receptacle's both inside and outside, I weld small jobs inside, and anything that would generate a lot of smoke goes outside, and of course welding on the tractor is an outside proposition.
James K0UA