My No 1 bike, C15, is still not starting, with the new rectifier, despite having a good current of 2.6A.
I have stripped down the distributor, and it is stamped to show that it has an advance of 12 degrees.
Is that right? I thought it was 10 degree on early bikes like my 1962 model.
What effect would it have?
Not much, is that the advance at the unit which would be 24 deg on the timing? I suspect so. Even then this is only 4 deg difference. Since the timing is set for full advance and that number is the amount it retards it should make no difference to the running and may make starting a bit easier.
Okay. I stripped, cleaned and reassembled the distributor, and now it is back on the bike with the timing set.
I am concerned about the compression. I measured it at around 60 - 75 psi. No 2 bike, which runs, shows 90 - 110 psi, and, according to an online search, it should be 110 to 140.
Would this stop it from starting? Maybe, but I imagine I would be hearing a pop at least.
Is that 60-75 kicking with the throttle wide open? That's very low and it may not start.
Have you tried putting some thick oil down the plug, this will seal the piston for a few kicks and show it its the rings.
Are the tappets set correctly so the valves close?
We managed to get it started, in the end, by setting the plug gap.
I have some classic car oil to put in (20/50?), so I'll do that next. And, I'll oil the bores as you say.
I am sure it still has 10/40 in it, as that is all I had at the time I was putting it back together. (It seems like a long time ago).
Any oil squirted into the bore via the plug hole will momentarily seal the rings if they were the culprit.
Always hold the throttle wide open when doing a compression test.
As already said, check the valves
I've you get an increase in compression psi with the oil , then the rings/bore may need attention
If there is no improvement with the oil, then the compression is creeping past the valve seats and a regrind will sort that
I squirted some oil into the bore and the compression raised from 75 up to about 90psi
OK at the very least it needs rings.