With my son's help, I finally got around to fitting the new Renold primary chain. Rather than buying the factory tool to lock the crankshaft drive to the clutch basket, I adopted the suggestion found in my Haynes manual to make a DIY version. The manual suggested steel of 70 x 20 x 5mm rounded at the ends, but I had a scrap of 6mm aluminium plate which I cut, filed and sanded for the same result and it worked a treat. Another special tool for the tool box...
The primary chain which was in there was 'in spec' and actually measured the same 21 pin length as the new Renold chain. Attached is a photo of the original; it is either 'Rolon' or 'Olon' preceded by an encircled 'R' for registered trade mark. If anyone knows who these chains are made by, I be interested to find out.
One of my previous purchases from HMC (besides the oil filter, O-rings and washers) included a set of replacement Allen key compatible crankcase screws, so I changed the LHS screws during this job.
Something that continues to puzzle me is that following a drain and oil filter replacement, 2 litres of oil takes the reading to the top of the sight glass. The manual states that I should have been able to put in 2.5 litres, so I'm cautiously watching the sight glass.
I didn't remove the RHS crankcase this time because I wanted to change the drive chain, sprockets and cush drive rubbers in one hit.
The leak shown here in the photo, I assume stems from the pesky kick start seal; just as well I erred on the side of caution and bought enough parts to cover most eventualities.
PS
I don't have a small child or dog in the household; those are puppy training pads which are very effective at absorbing all sorts of fluids including oil...