G'day JS Fixings into alloy are Whitworth Thread. The other fastenings are Cycle "CEI" otherwise known as BSCy. Cylinder Head bolts are BSF by my reckoning, perhaps someone can confirm.
Dismantling is straight forward, look for cracked castings and ill fitted bodged and pulled threads.
Here are a few things to help make it easy when you go for the big reveal.
Locknut and Oil pump drive on the end of the crank, timing side, have a LEFT HAND THREAD. Use a homespun puller to remove the pinion on the crank, not a big hammer. With the pinion in place the crank won't pass thro' the timing side bush.
Drive side cush nut has a tightness figure of 65/75 ft/Lbs, make beg borrow a proper 4 peg something to undo it, not the hooligan's method.
Cases will split with all the fixings removed. Don't miss the internal nut by the camshaft trough. Camshaft drive gear can remain attached, thread is normal right hand, then removed when you have the cases apart and can easily hold the cam still. Some cam gears slip off easily, tight ones need a puller using the two threaded holes. Take care with the pesky camshaft keyway when reassembling. The key displaces and digs into the bush. If the cam and bushes are OK, the cam can remain in place, undisturbed, as this does not hinder splitting the cases.
Con rods ...drive side has one with a small hole in the web just above the big end eye. This should face towards the flywheel.
That's the basics, now find some spanners that fit as a first step.
Cheers
Swarfy.
