150 hp johnson engine won't shut down

[wastedawayinkeywest]

i have a 150 hp johnsom n v-6 when i turn off the key switch the motor drops 400 r.pm but keeps running. turn off the battery switch. keeps running. turn off key ..keeps running. pull the emergency stop switch. keeps running. i have checked all the wires in the power head none seem to be shorted or rubbing. anyone had this problem?

 

[tashasdaddy]

Re: 150 hp johnson engine won't shut down

black yellow wire is the kill wire, it has a problem, or bad ignition switch. you can easily, ruin your electrical system by disconnecting battery from running motor. you probably have already damaged the rectifer, by disconnecting the battery while running.

 

[emdsapmgr]

Re: 150 hp johnson engine won't shut down

You don't say what year your engine is. Would help to know the ignition system that the engine has. Could be a defective ignition switch or (if you have the dual power pack system) you could have a defective pack. I had your similar experience and found that one of my packs was bad-kept firing one cyl bank when turned off. Replaced the pack and problem cured-the engine shut off.

 

[boobie]

Re: 150 hp johnson engine won't shut down

Model # ???

 

[ezeke]

Re: 150 hp johnson engine won't shut down

The 1985 models have two powerpacks and one of yours is not grounding out when you turn the ignition key to off.

This means that you either have a problem in the black with yellow stripe wiring between the large red plug and that powerpack, or the powerpack itself is bad.

You can check the wiring with your ohmmeter.

 

[gizzy]

Re: 150 hp johnson engine won't shut down

I have the same problem. I have a 1991 175 Johnson and I rewired and repaired all the wiring 1 at a time. It starts fine. I just bought this engine and I used to have a 1989 Evinrude 150 harnessed to my boat. I have 2 black yellow wires and 2 beige wires all paired up. I can't figure out where to hook them up at from the old harness on my boat. I guess what I'm trying to say is. Are these my shut off wires?

 

[emdsapmgr]

Re: 150 hp johnson engine won't shut down

There is a single black wire with a yellow tracer that goes from the M terminal on the key switch to the power pack through the red plug under the cowling. When the key switch is off, the M terminal grounds out the that black/yellow wire (and the power pack.) A beige (light tan) runs from these engine-mounted components: vacuum switch, both heads and the VRO- to the horn in the control box.