I'l' stay out of the GMS/bearing portion of the discusion but I must add to Whyes comment.
I was rebuilding a HB .61 PDP. New piston and ring. (Dykes). After the rebuild I decided to shoot a little WD40 down the carb.
I was holding the engine in my hand at that time and then decided to flip the engine over to work in the WD. Bad Idea.
The engine fired and as it jumped out of my hand, wacked me on the wrist resulting in a nice Goose Egg. Now all you engine guru's know that Dykes ring engines have very little compression, so never ever do this dumb thing like I did!
On the other hand, WD40 is the best thing I have ever found to get an engine started in cold weather. A small squirt will bring an engine to life like its a warm summer day.