1991 LT80 Rebuild
 

I was in the process of replacing the cooling fan and rebuilding the cylinder on my LT80 when I noticed spinning the crank by hand sounds like there's debris in the rod bearing. I am going to pull the rod and crank out for inspection/cleaning then decided I might as well basically pull most of it apart to clean the years of built up junk and make sure I need no other parts. Does anyone have torque specs for the rotating assembly or maybe a list of all torque specs? Also should I be worried about this discoloration on the clutch?

https://scontent-lax1-1.xx.fbcdn.net...87&oe=560BC138

100-110 inch pounds on the head nuts.
All else I just tighten well.
The clutch nuts are best installed with a impact wrench.
Got hot!~ Maybe the pads wore out. They wear forever it seems tho. Take em apart and see.
I suspect your feeling the main bearings being bad.
FYI: I use Koyo bearings on the crankshaft (main bearings).

Thanks for the info! It was taking up too much space in the garage apart so I installed the top kit (cylinder, piston, etc), new cooling fan, removed the oil reservoir, oil pump piston and cam, and put it all back together. With the generic 1:32 premix it runs much better now and barely smokes! The only problem I see is I have fuel/oil very slightly squeezing out around the spark plug. Now I did have to put a thread saver in the head because a previous owner really did a number on it. Can I just double up on spark plug sealing washers or do I need to replace the head? Is a head available?

I get heads off ebay. I don't pay over $25.
I'll send you one shaved .030 for $40 shipped.