I have a 2007 Honda 420 Rancher 2x4 four wheeler. I over tightened the oil plug and the aluminum threads inside the case have broken off and are inside of the engine. Of course I am assuming the broken pieces are still inside the case. I didn't see them when I drained the oil. I took the bike to the store where I purchased it and let them take a look at it. They said there are 2 options:
1. Let them replace the case...cost ranges from 1600.00 to 1900.00 after everything. (take out engine, new seals, bearings, ect, replace engine.)
2. Take it to a welding fabrication shop and see what they suggest.
I went with the 2nd option first. They (welding shop) want to drill out the drain hole bigger and get a hose and see if they can suck out the broken pieces then weld a new aluminum drain plug over the drilled hole. The broken pieces probably will not fit through the drain hole.
I did ask the Honda dealership about this and they said just make sure there will not be any metal getting inside the case that should not be in there and this will not void my service agreement.
Any suggestion are gladly appreciated.