If im understanding correctly your just remove the clutch assembly from the inside of the motor. If thats all it is theres a nut then antirotate washer behind it. Well my first tip is when tearing down anything with lets say over a year since disassembly i suggest some sort of impact. Although they do 4x the work they also apply less stress on parts b/c their not using slow brute force instead fast hard breaking force which also simulates the pre loosening action of hammer and punch creating a vibration to initiate the initial breaking loose. That being said the nut tightens clotckwise loosens counter. I dont recall a single.item on my 1976 mr 250 elsinore being " left.hand thread" and im almost certain these motors will interchange almozt all parts. If you still have questions im gonna be placing a sort of tutorial via youtube this week showing a complete engine teardown of a 76 eli 250 tranny included so you may wanna use these to answer your arising questions or email me @
nateswebnathan@yahoo.com and i'll get back with you at my earliest convenience. I'll leave.the youtube links this week after i post them