Have you checked the oil in the compressor? The motor is either overloaded or the electrical supply to the motor is inadequate. Check the amperage draw of the motor while it is running.

Could my friend have cooked it by running it a few times with basically 110 instead of 220?

Yes he could have damaged the motor.

The sneeze valve or check valve could be busted. Essentially, when the compression shutsdown once it hits the maximum pressure has two things:

1. A checkvalve keeps the tank pressure from back feeding the compressor.
2. The thing I call the sneeze valve opens to release the left over pressure from the compressor.

The next time the compressor wants to run the pressure trapped in the tank may prevent the motor from starting.

I know the voltage is good but no idea on the amps..motor is a 15amp. On the sneeze valve deal I can see where that would be an issue but its falling short of reaching max pressure and I would think it would atleast try to start and if the back pressure was present it would kick the reset, but she never tries to restart. It's just down until I hit the reset. I'm at a real loss here on this deal...kinda odd symptoms for sure and trouble shooting it past where I have gotten so far is tapping into my lack of knowledge in a hurry. On checking the amps when it's running, what is the best way to go about that? I think I have an inductive ammeter here somewhere...can I just hang it on the line to the motor and see what it says that way?
Thanks for all the ideas thus far!
Todd

Well I went and checked and the inductives I have are all DC units. Since this has a thermal reset does anyone know if that is something I can replace? I am wondering if perhaps it could be weak..

I had a commercial freezer unit that did the same thing, ran and then slowed to a stop. Let it cool down and same thing. Pulled it forward and there was a pool of oil, had it repaired and recharged and still did the same, no oil.

As bus_driver says; check the oil. And then start replacing stuff.

"Since this has a thermal reset does anyone know if that is something I can replace? I am wondering if perhaps it could be weak." The proper procedure has already been posted. Check the running AMPERAGE! If you do not have the equipment to do that, buy, borrow, rent, or hire someone who does. Diagnose the specific problem and repair it.

Amperage was fine so yesterday I did some more checking and noticed the unloader seemed to be leaking off and on..not much but a little, I am not how things got this way and I guess it's been that way awhile while my friend had it, but the unloader pin that sticks down was not working correctly and seemed to be hanging up. I went this morning and purchased a whole new switch assembly and everything is working good now..she unloads and shuts down at 125 and comes back online at 90. I think I am back in business hopefully.

Nice job sticking with this problem until you fixed it. In our throw-away society, that kind of effort is getting rarer each passing year.

Congrats!