ORIGINAL: BarracudaHockey
You should break it down and inspect the bearings. There's things you can do depending on the condition and run time of the motor. For cleaning gunked up metal parts, old green cheap antifreeze in a crockpot on low works wonders but you have to be careful with animals and not to breathe the fumes and not to cook food again, I have a yard sale 5 dollar crock pot that works like a champ.
Barracuda, I had a buddy that told me about that "old control liners secret" for cleaning engines. Well, I got all set up and dunked my Supertiger 2500 for a day and it turned it black and ruined the look of it. It still runs, but looks like a real junker. I tried to clean it up with a toothbrush and ended up with a small wire brush, but you can't get into all the small spots. I wasn't impressed with that little secret.