Pete,

You are correct, When it backfired the last time it blew the left crank seal off. That's a good thing because now i know why it wouldn't restart. I looked carefully at the crank play (movement) and its the bearing itself and there is some play between the crank and inner bearing race. I am hoping the bearing is just worn. The center cases are good. 

Pulled the engine out yesterday. going to split the cases and rebuild the bottom end. Thinking about going right to 2nd over to have the cylinder bored and past on 1st over just in case it didn't clean up good with 1st over. 

Will be replacing crank bearings, all seals, gaskets, clutch plates and friction plates and what ever else i seen worn. New top end. Should run nice after it's done.

 

Yep ran my race bike for 4 years, no problems.

Went ahead and split the cases today. Took about  a hour. surprisingly in good condition besides the crank bearings and seals. Just waiting on my BIG partzilla order to arrive so i can slap it back together.