11-07-2022, 11:26 PM
(This post was last modified: 11-07-2022, 11:28 PM by A G Wood.
Edit Reason: added words for clarity
)
Your advise would be welcome.
My 10 cents:
-definitely 4.5v or better at the coil primary during crank (If you're using the electric one not the human one)
-No movement from ammeter would be normal if the points happen to be open. A cause for concern if they're closed.
-Fig 77: Rotor shorted to earth?
-I don't personally set much store by spark plugs/leads sparking in open air. I have a modified extended nose plug with no earth electrode I use for that job to simulate the influence of compression on the HT voltage for roadside tests, but I've never tried it on a 6v system.
-You may still have a weak coil which is incapable of producing enough HT to jump the added gap between the rotor and the cap electrodes.
-The capacitor, in addition to damping down sparking at the points, also acts as part of a resonant circuit with the coil windings causing 'ringing' which acts to increase the spark duration. So a capacitor issue can cause starting issues when the demand for HT is greatest.
You may have to start with substitution-based diagnosis, as always beginning with the least expensive component of course.
My 10 cents:
-definitely 4.5v or better at the coil primary during crank (If you're using the electric one not the human one)
-No movement from ammeter would be normal if the points happen to be open. A cause for concern if they're closed.
-Fig 77: Rotor shorted to earth?
-I don't personally set much store by spark plugs/leads sparking in open air. I have a modified extended nose plug with no earth electrode I use for that job to simulate the influence of compression on the HT voltage for roadside tests, but I've never tried it on a 6v system.
-You may still have a weak coil which is incapable of producing enough HT to jump the added gap between the rotor and the cap electrodes.
-The capacitor, in addition to damping down sparking at the points, also acts as part of a resonant circuit with the coil windings causing 'ringing' which acts to increase the spark duration. So a capacitor issue can cause starting issues when the demand for HT is greatest.
You may have to start with substitution-based diagnosis, as always beginning with the least expensive component of course.