Message text written by George Richardson
>Although you're correct about the gap decreasing as the block wears, the
high voltage spark can't ever jump across the points. They're only
connected to one end of the high voltage winding of the coil. The other
side goes through the rotor to individual spark plugs, which unless the
rotor, cap, plug wires, or timing is bad, is the only place the high
voltage spark can go.
What does happen is that as the gap closes, current runs through the
points and coil for a longer period of time. The most immediate effect
is that the points and coil run hotter. Sometimes with plastic mounted
points, this causes them to melt. It can cause excessive arcing across
the points from the low voltage winding of the coil. And it can result
in less high voltage spark to the plugs.
<
Actually, as the block wears down the points open later and the timing
becomes retarded (much like the owner of my car ;-) ehem!) and
eventually reaches the point where they don't open at all. No open - no
spark.
Dave
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