Kill wire giving me the jerks

[HenryB]

I am troubleshooting the black/yellow kill wire on a Johnson 130 hp (all the plugs removed)

If the engine rests for 24 hours, with the ignition switch on, and a continuity check at the black/yellow wire shows full open, the plugs fire, and will continue until the switch is turned off (that is fine until I shut the ignition switch off).

Every time when I turn the switch back on, no fire at any cylinder.

And when I disconnect the black/yellow wire at the power pack, I get spark at all four cylinders.

When I do a continuity check with the switch on I get approx. 600 ohms instead of a full open reading.

That is where I am at the moment. I thought I’d pass it by here to get a clue where I should start looking for the glitch,.

Thank you.

 

[Silvertip]

Disconnect the wire on the two "M" terminals on the ignition switch. Connect your ohm meter to those two terminals (on the switch) and cycle the key between OFF and RUN. You should read continuity in the OFF position and OPEN in the RUN position. If at some point you see continuity in the RUN position, you need a new ignition switch. You might also check this while turning the key between START and RUN, then to OFF, then to START and back to RUN etc., It would still indicate a switch problem. If there is no indication of a problem with the switch, then ignition switch/kill switch wiring is the culprit. That wiring goes back to the ignition module at the engine so check back there as well. Just the movement of the engine may be causing the kill circuit problem.

 

[HenryB]

No problem with the switch. Checked the switch a couple dozen times and not once failed. I'm getting a high ohm reading in the off and on position at the power pack junction, with the black/yellow wire disconnected. It pins out and then some at the highest ohms setting.

I'm also doing an ignition test at the same time. The timer base is showing 1.5 volts (DVA) all around. The spec.I have says over a .5 volt is sufficient, 1 1/2 volts??

The motor is a 130, 1998, 4 cyl. Johnson. The Power Pack output spec. calls for 150 volts. I'm getting 107 at three cyls. and 80 volts at one of them.

 

[boobie]

How are you checking your spark ??

 

[HenryB]

I am using a Sperry multimeter and an ES adapter. The adapter prongs are wider than the holes in the meter and am using jumpers. The spark appears healthy using a gap tester.

Early on I did notice a periodic gap in the spark at the cyl. with the low voltage reading. About every couple of seconds no spark for a split second. That was in the evening when I got good visibility. I cannot see a repeat in daylight.

 

[boobie]

Not familiar with your meter but as long as you have a 7/16" open air gap, you're fine.