robert nanzig wrote:
> I put out an SOS this morning because my SV would not start and
> there was no spark at # 1 and 2 cylinders. Jarrid and Jim Leach guessed
> correctly that the points were not opening properly ( Pertronix unit now
> on order) and I made an interesting discovery along the way. I wanted to
> turn the engine to watch the points open and remembered my brother
> telling me there was a button on the back of the starter relay on his
> Triumph that will advance the engine. Sure enough, we have the same
> thing. The thing I don't understand is why, with the ignition key off,
> was there sparking at the points?
>
> Rob Nanzig
> 67SV
The answer is simple, and only applicable to SVs.
The starter relay coil is wired to the points side of the ballast resistor,
which effectively shorts the ballast resistor during starting to compensate
for the voltage lost to the ballast resistor, thus giving a hotter spark.
The typical ballast drops 4 or 5 volts, so the coils gets 8 or 9 volts
under normal circumstances, but when the car is cranking, the battery
voltage drops to 8 to 10v, which leaves the coil only able to give
a weaker spark, which sometimes isnt good enough.
Jarrid Gross
This archive was generated by hypermail 2b30 : Tue Sep 05 2000 - 10:51:47 CDT