Flywheel nut torque 50 ft.lbs.
I think the factory manual says to put a new nut in, does not matter if nylock or not, but I always reuse mine and sometimes I put some small amount of threadlock liquid if it is a nut without nylock.
The imported thing is to check the cranktaper, taper in the flywheel, flywheel key and the grove from bad surface.
If bad surface lap the taper with some valve grindingcompound such as Carborundum.
Then torque to right value.