The fried coil in the Atomic 4
On me last trip the coil got really hot. Its been an ongoing annoyance that the engine would quit just before my destination ,right after a power change. Also the batteries were draining quite rapidly .
Well it seems that the resistor wire had failed and was feeding 14.5v directly into the coil. The last trip it got so hot you could not hold it, ultimately frying the resister wire from the switch all the way back to the coil in a smoke test. It really stinks , literally.
I pulled out the old coil and trashed it. Some posts say you can still use it when it cools down, especially the ones that are oil filled (old style) but i did not want to take any more chances , I threw it in the trash and replaced it with another old style, I could have used one with an internal resistor but those are solid carbon pile coils also subject to a much higher rate of failure than liquid filled.
I placed a ceramic drop down external resistor on the wall mounting it on a cork spacer. The resistor gets hot when it drops the voltage down from 13.5 to 9, and mounting it to fiberglass bulkhead is not a wise move.
This repair has seemed to solve the problem, I have now run the engine for over 12 hours on and off with one run almost 8 hrs and no problem.
Yes the coil does get hot under normal use but not to the point where you cant touch it
Dropping the coil voltage also changed the way the engine runs I'm going to assume this is because of the spark to the plugs is much cleaner now. I no longer get that occasional misfire under load. This may also be because I changed all the wire harness while I made the adjustment. In any case the throttle throw to get the engine to 2000 rpm is now much larger and smoother, without changing any of the mechanical linkage divestments.
I also set the timing to 17 deg BTC under load at 1800 rpm this improved the shaft HP output quite a bit.
Reverse is now a pleasure instead of an adventure Time will tell but im happy with these changes
Well it seems that the resistor wire had failed and was feeding 14.5v directly into the coil. The last trip it got so hot you could not hold it, ultimately frying the resister wire from the switch all the way back to the coil in a smoke test. It really stinks , literally.
I pulled out the old coil and trashed it. Some posts say you can still use it when it cools down, especially the ones that are oil filled (old style) but i did not want to take any more chances , I threw it in the trash and replaced it with another old style, I could have used one with an internal resistor but those are solid carbon pile coils also subject to a much higher rate of failure than liquid filled.
I placed a ceramic drop down external resistor on the wall mounting it on a cork spacer. The resistor gets hot when it drops the voltage down from 13.5 to 9, and mounting it to fiberglass bulkhead is not a wise move.
This repair has seemed to solve the problem, I have now run the engine for over 12 hours on and off with one run almost 8 hrs and no problem.
Yes the coil does get hot under normal use but not to the point where you cant touch it
Dropping the coil voltage also changed the way the engine runs I'm going to assume this is because of the spark to the plugs is much cleaner now. I no longer get that occasional misfire under load. This may also be because I changed all the wire harness while I made the adjustment. In any case the throttle throw to get the engine to 2000 rpm is now much larger and smoother, without changing any of the mechanical linkage divestments.
I also set the timing to 17 deg BTC under load at 1800 rpm this improved the shaft HP output quite a bit.
Reverse is now a pleasure instead of an adventure Time will tell but im happy with these changes
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