I had been nicking a few bits off it for the 3AJ kick start conversion when I realised that there was very little wear on most of the engine
I was hoping that when the chain had come off and broke the side case that maybe that was all the damage, I know oil pressure would have been lost as the feed had been smashed but surely the rider would have shut the motor down 
So I ripped the motor out and plonked it on the bench, it was then I saw black silicon protruding from the rocker cover 
Man they had gone to town with the black shit, I also found it on the clutch cover as well even though it had a gasket 
Pulled the head off and and it has the original piston and the valves look new, slid off the barrel and the first signs of oil starvation are obvious with some heat marks on the piston and some wear on the little end of the conrod.This is what happens if you go bananas with silicon or any gasket goo, it basically melts down with the oil and blocks up the pick up!
The oil pump looks new.
As does the clutch, the motor has never been split as the locking washers were original.
The gear box has a tiny bit of pitting on 3rd gear but everything else is good.
I am going to take the broken case in to my mate to see if he can weld and re-machine it.
I am thinking about building a rat bike with this motor, basically making a complete bike out of all my spares with out spending much money, no powder coating ,zincing etc ,just all my old stuff bolted up and it will look 31 years old
Regards Eric
but it seems like I have a lot of ghosts of bikes from the past and maybe I can make those spirits happy by combining them and releasing them for one more life 
My brother has a set for the front he will lend me until they are back in stock. Anyway I laced up the rear today in about 1 1/2 hrs and got it down to about 10 thou run out 
