No Spark

MKL · Oct 23, 2012

MY A has intermittent spark. Always has it from the coil wire, but not @ the spark plugs. Cap? Rotor? Was running fine then nutin.

Janicholson · Oct 23, 2012

Wires cap and rotor are most probable. Test each wire with an ohm meter. if resistor wire (not best) they should be about 10,000 ohms or less. if wire they should be basically no resistance. Look for tracks and cracks on the rotor and cap; drying it with ablow dryer and using clear acrylic spray on it may make it work till a new cap can be purchased. Jim

old · Oct 23, 2012

First check point gap at all 4 lobes on the distributor shaft and make sure the points open very close to the same on all 4. Next if that checks good spray the inside of the cap with starting fluid and blow dry it if you have a compressor. If you see any lines after doing that on the inside of the cap your cap is cracked where you see those lines. If that is ok try a new rotor I have seen those go bad out of the clear blue but then I also keep old ones on hand so when and if the new one goes bad I have a spare

gene bender · Oct 23, 2012

You didnt say magneto or dist. Have you ever replaced the wires with copper. How about some new plugs?

Dan Bear Kelley · Oct 25, 2012

Wouldn't hurt to replace the condensor, either.

MKL · Oct 25, 2012

Thanks. Replaced the cap/rotor. After a couple tests I'm losing the spark through the rotor somehow. I put a piece of mechanics wire from the center terminal of the cap directly to a wire terminal,removed the rotor,installed the cap and cranked it. The ignition cable I hardwired had very good spark.

Janicholson · Oct 25, 2012

If the rotor is not pointing to a plug wire terminal when the points break open. (spark happens)
the spark will not go to the plug, but may jump to ground in the distributor. If it is a magneto, the rotor can get out of time with the cam that opens the points. if it was taken apart, this is probably what happened. The wire will redirect the spark to one plug even though the rotor is out of time. The rotor does not touch the terminals, it just clears it by a few thousandths. If it is a point and coil system, the rotor could be the wrong one, or the little positioning lug in the rotor could be broken off. Jim

MKL · Oct 25, 2012

I took it apart but only as far as the points. Never took it off the machine. The rotor lines up with #1 @ TDC and impulse seems correct. I even tried a fiber drainplug gasket to shim the rotor out a little to make sure I had contact with the cap.

No Spark

MKL

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Janicholson

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old

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gene bender

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Dan Bear Kelley

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MKL

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Janicholson

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MKL

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