I'm looking for some advice/backup on setting up the timing on my 1965 B40F.......after a long pause since I last tried....but it looks like I cleverly set completely wrong, changing the cam position.... So that I now can't rotate the points plate enough.....so I'll have to move the cam again. However, my brain needs to work out how far and in which direction, and I'm struggling ( I presume I can't rotate the cam without removing the points plate first?)
Please let me know if the following sounds correct, or if not why:
I presume I want to move the cam so that the pillars are central in their slots on the points plate, when:
a) the engine is at/close 33.5 degrees before TDC(compression stroke) having removed backlash;
b) and when the auto-advance is turned anti-clockwise to full advanced;
c) and when the heel of the points is close to the point where the points just start to open ?
When the engine turns forwards, the cam rotates anti-clockwise. The cam has a lower flat section, when the points are closed........... so am I correct that the points start to open on the clockwise end of the lower section of the cam/transition to higher section ?
Once the cam is rotated to the approx. correct position and nipped back into place ....and points set on higher part of cam, then I presume return the engine to comply with a); b); and c) above and finely adjust/rotate the points plate using a battery and bulb so that the bulb is on at >33.5 degrees before TDC, but out at 33.5 degrees and lower.
My head is thinking the above is correct ?
Also:
I changed the capacitor when I last fiddled with the bike....but it's longer and very close to case ( photo attached) I can get a 0.05mm feeler in between the end of the thread and the case. Will such a small gap be a problem ? plus no felt oiler on the capacitor. Do I need to add one and oil ?
You're correct in your procedure.
Points plate slots central on their screws and AR unit loose on its bolt
Personally, I use a multimeter on Beep to discover when the points open,
1 clip on earth and the other clip on the points wire( discon from coil)
Get your piston at the correct position btdc and then rotate the AR using a pair of long nosed pliers on the cam to hold it advanced.
Rotate gently until the Beep stops and points just opened
Lock up central bolt.
Hope that helps
It sometimes helps if you start by marking the point on the cam with a felt pen where the heel just begins to open the points - this needs to be done with the AR units bolted down. You can then use that mark to do the initial alignment of the AR unit rather than relying on a DVM beep that will be affected by the AR unit not being tight on its taper. Otherwise, the procedure described above is about right.
Thanks both.
So sounds like I should be able to tap the cam free & turn it with the points plate in situ? Correct ?
In which case I'll both mark and try that.
Yes - that's normally the way you free the AR unit each time. It's just a question of how many attempts it takes to get it positioned close enough to then be able to fine tune the timing by moving the points plate. The last time I did this procedure, the engine was fortunately on the bench which made it much easier ;)
Well I'll be sitting on the garage floor with a dodgy back.....so fingers crossed it goes OK and I can stand back up!
Thanks again.