I also do not like using tools without a proper ground, a used compressor I bought a while ago had the ground prong ripped off, I changed the plug to one that had the ground before use. If I would've known I could've bought one of these off CL for about 50$, I would have just bought it! Learned the lesson of not borrowing anymore things. So I took it apart today that I had some time. It turns out the bottom bearing that holds the motor shaft, seized up, and it spun within the plastic housing and it spun at the speed on the motor! It burned some of the plastic that holds the bearing center I believe this is what cause the smoke, and is what causes some resistance when spinning the blade with the motor off. I am going to replace the bearing, hopefully the burned plastic will not cause any trouble. The brushes look good on the contact points but one side of each brush is chipped. Should I replace these to? heres a pic of the brushes. They both look like this, just on one side. Heres a picture of all the burnt plastic pieces I removed! I searched for the parts on that site, all the info I could get from the bearing is AOKE 6200Z. This came up, do you guys know if its the same? http://www.ereplacementparts.com/6200zz-p-969436.html and for the brushes, idk what to search. Model numb. on the motor is rm872. serial no. 112297. Thanks everyone who has helped me with this!