1
CB350/400 / Arcing points
« on: March 22, 2024, 03:23:08 PM »
It's a standard battery and coil system
Points 1-4 are arcing excessively - the spark is much the same as at the plug and it causes a misfire, which clears for a while when the points are cleaned.
The condensers are new pattern DS parts; I've tried swapping them over with the 2-3 set and also returned the original (40 years old) one. Whilst you can convince yourself that there is a marginal difference, before long it's points 1-4 that are troubling.
The LT resistance of the coil is 4.2 ohms (same as the other coil). I can't yet see how it can be caused by the HT side but nevertheless it has a resistance of 30.9k ohms (only 23.4k ohms for coil 2-3). The plug caps are 8.3k & 8.6k (4.3kx2 for plug caps 2-3 - which are a longer reach type).
New set of NGK plugs.
Any thoughts on what is causing the arcing would be most welcome
Points 1-4 are arcing excessively - the spark is much the same as at the plug and it causes a misfire, which clears for a while when the points are cleaned.
The condensers are new pattern DS parts; I've tried swapping them over with the 2-3 set and also returned the original (40 years old) one. Whilst you can convince yourself that there is a marginal difference, before long it's points 1-4 that are troubling.
The LT resistance of the coil is 4.2 ohms (same as the other coil). I can't yet see how it can be caused by the HT side but nevertheless it has a resistance of 30.9k ohms (only 23.4k ohms for coil 2-3). The plug caps are 8.3k & 8.6k (4.3kx2 for plug caps 2-3 - which are a longer reach type).
New set of NGK plugs.
Any thoughts on what is causing the arcing would be most welcome