My favourite motor to work on. I've done so many of these I've forgotten how many.
Just a few points.
Primary chains are very thick with mulitple link plates, (pic is a primary chain BTW) camchains are like pushbike chains like in the post 54 pics. You look like you haven't got down to the primary chain yet but when you do you'll see the clear difference. On the primary chain subject, check under where it runs, there is an oil gallery tunnel right under it, if the chain is getting tired you'll see where it's been gouging away at this tunnel, it's also the noise you get at tickover when this chain is lashing around, goes almost as soon as you rev the engine as it comes under load then. Always replace this chain when you've got the motor down this far. Also check the cush rubbers inside the primary chain sprocket housing, these tend to get hard as they age, see if you can move the sprocket whilst holding the housing, if you can then you need new cush rubbers. You'll see what I mean when you get to it.
The oil restrictor missing, has the motor ever been apart? they do tend to stick inside the barrels when lifted off but they don't tend to go missing, they are either still locked into the crankcase or stuck into the barrel, they don't tend to fall out. If it was missing it would account for the poor state of the cam journals which to me look like they've been running short of oil.
Rocker arms look shot to me, that line in the centre is a clear indicator they are buggered, again oil shortage would account for that.
Main bearings and big end bearings- check the state of them when you split the casings, they should look unmarked or evenly marked, they shouldn't look like the cam journals if you get my drfit, light marking is fine. Same goes for big end bearings, mark the rods as you remove them, make sure they go back onto the same crank journal. Plastiguage isn't needed to order new bearings, I was a Honda mechanic for a LONG time and we never used plastiguage at all. Honda kindly marked the casings and crank so you can figure it out. Look at the back of the engine, you'll see 5 letters, something like AABAA. These correspond to the crank journals, the crank is also marked, however Honda used a sort of indelible ink which tends to go fainter the older the engine, the crank webbing has these, it will be a number, either 1 or 2. So if casings were BBABC for instance and crank was marked 11211, then correct bearing size would be B1, B1, A2, B1, C1. Workshop manual will tell you the colour you need, same goes for bigend bearings. Four letters on the crank webbing and 4 numbers on the rods. Easy once you know the trick, only works however if the crank and rods show no signs of excessive wear but as the crankcasings are protected by the shell bearings they tend to be ok, only exception is where the shell bearing spins. Cranks tend to be ok unless marked which you can clearly see.
