25HP Johnson Ignition

[CardsFan82]

Bought 1978 jon boat with 1978 25HP Johnson tiller handle year ago. Rebuilt carb and replaced plugs. Used it soon after purchase, but not since. Now the ignition won't work. I've ran a jumper wire from the battery to the starter and it cranks, but won't do anything when using key switch. "Control box" which appears to be stock, has 4 switches...ignition, red stop button, lights, and a momentary switch that i don't know what it is for.

What trouble shooting proceedures do i need to take? Can i use a jumper wire on the ignition switch to see if it is the problem and which terminals do i jump?

Any idea what the momentary switch is for?

Any help would be greatly appreciated!

Thanks in advance!

 

[Robert R Ellis]

Re: 25HP Johnson Ignition

Hi,

I'm a newbie so take what say with a grain or 2 of salt.

I'm not sure how tiller electric start works but a similar runabout has an electrical box in the back of the boat. The battery terminal wires (among others go in here. It also holds your solenoid. When the key is turned to the start position one of the two smaller gauge wires hooked to the solenoid (in my experience it's white) should receive 12V. If it doesn't you have a ignition switch or wiring to/from the ignition switch problem. If it does get the 12v, it seems likely the solenoid is shot. No worries there, they're not expensive.

Thinking of the momentary switch - can you follow the wire to see where it leads? - my boat has one for an electric choke, it could be a horn or even a bilge pump I suppose.

I was interested in what you said about a 'stop light'. Is that an engine overheating light? - seems a good idea but none of my boats have one.

Robert

 

[F_R]

Re: 25HP Johnson Ignition

Got a multimeter (voltmeter)?? Know how to use it?? That absolutely is the best way to figure out what is wrong. Or you can guess. Most people wind up buying parts that they don't need.

 

[Haffiman]

Re: 25HP Johnson Ignition

Did you hook up the safety switch lanyard?

 

[CardsFan82]

Re: 25HP Johnson Ignition

No solinoid in the box.

Manual choke and no bilge pump.

No "stop light" i said it was a red stop button and a switch for lights.

 

[CardsFan82]

Re: 25HP Johnson Ignition

There is no safety switch lanyard option.

Messed with it a little last night. Tried the ignition key first thing just to take a "shot in the dark" to see if it would work and i could hear a "click" like the starter tried to crank as if it had power momentarily, but it only did it the first time. Second and third tries did absolutely nothing like the battery was dead. Kind of did it before and that's why i took the battery to be tested and it checked out okay.

 

[CardsFan82]

Re: 25HP Johnson Ignition

Messed with it a little last night. Tried the ignition key first thing just to take a "shot in the dark" to see if it would work and i could hear a "click" like the starter tried to crank as if it had power momentarily, but it only did it the first time. Second and third tries did absolutely nothing like the battery was dead. Kind of did it before and that's why i took the battery to be tested, but it checked out okay.

 

[Robert R Ellis]

Re: 25HP Johnson Ignition

Again, I'm new to this so ....

I can't imagine an electric start system without a solenoid. If you follow the positive lead (red) from the battery it should go directly to the solenoid - another heavy gauge cable should connect the solenoid to the starter motor - oh ... maybe the starter and solenoid are kinda mounted together but ... whatever.... the smaller gauge wire going to the solenoid should get 12v + from the ignition switch when the switch is held in the start position. Test with either a multimeter or one of those cheap automotive circuit tester thingies - you know what I mean, shaped a bit like a pen and lights up when 12v is present. One really good thing you know is that the starter motor itself is ok since it cranks when you bypass the solenoid with a jump wire!

Odd about the momentary switch - maybe it's for an option your boat or motor didn't come with.

 

[CardsFan82]

Re: 25HP Johnson Ignition

Thanks!

I'll test the solenoid and see what happens.

The momentary switch is wired but I still have to trace the wires to see what it operates. Just thought I'd ask to see if someone would know off hand.

 

[milliesdad]

Re: 25HP Johnson Ignition

Have you charged the battery? Check the electrolite level, fill to split rings with distilled water, put on a slow charge.

clean ALL electrical connections.

Then try it again.

 

[CardsFan82]

Re: 25HP Johnson Ignition

Had the battery tested at battery supply house and it tested fine.

Like i said, when using a jumper from the battery to the starter, it cranks fine, but nothing with the ignition switch.

 

[Robert R Ellis]

Re: 25HP Johnson Ignition

ha ha - this probably a really dumb question but ... is the positive lead from the battery to the switch fused and if so have you checked it?

R.

 

[CardsFan82]

Re: 25HP Johnson Ignition

No fuse

 

[jasper60103]

Re: 25HP Johnson Ignition

There is no safety switch lanyard option.

Messed with it a little last night. Tried the ignition key first thing just to take a "shot in the dark" to see if it would work and i could hear a "click" like the starter tried to crank as if it had power momentarily, but it only did it the first time. Second and third tries did absolutely nothing like the battery was dead. Kind of did it before and that's why i took the battery to be tested and it checked out okay.

Since you heard a click from the solenoid, I'm thinking it could be a wiring problem or the ignition switch.
Lets bypass the ignition switch and see if the starter cranks.

Basically we're making a momentary switch.
One of the smaller terminals on your solenoid should connect to the ignition switch.
Using a piece of wire (household wire is fine), momentarily connect ("touch") this solenoid terminal to your battery (+).
If the starter cranks then I suspect a wiring problem between the solenoid and your ignition switch, or the ignition switch itself could be faulty. Repeat the test a couple times to be sure. Good luck.

 

[Haffiman]

Re: 25HP Johnson Ignition

Suggest you post some pics of your set-up, does not quite seem to be according to the book.

 

[CardsFan82]

Re: 25HP Johnson Ignition

Thanks! I'll try that next.

I did use my multimeter and I do have 12.5 volts at the terminal going into the solenoid. I checked the two small terminals (both wires are white) on the solenoid as I turned the ignition. One of them had no voltage (guessing ground lead but can't see where it goes) the other registered LESS than 1 volt. Also checked the terminal going to the starter as I turned the ignition and it didn't register ANY voltage.

If I try the jumper wire for the "momentary switch" and it does NOT crank, does that mean the solenoid is bad?

 

[jasper60103]

Re: 25HP Johnson Ignition

Thanks! I'll try that next.

I did use my multimeter and I do have 12.5 volts at the terminal going into the solenoid. I checked the two small terminals (both wires are white) on the solenoid as I turned the ignition. One of them had no voltage (guessing ground lead but can't see where it goes) the other registered LESS than 1 volt. Also checked the terminal going to the starter as I turned the ignition and it didn't register ANY voltage.

If I try the jumper wire for the "momentary switch" and it does NOT crank, does that mean the solenoid is bad?

Possibly, but you heard it click before, so I'm thinking it's your starter switch or bad wiring based on your test above. Where you measured less than 1 volt, it should have been around 12 volts. The other terminal where you didn't measure any voltage is a good sign, because it should be ground. Checking it for continuity (zero ohms) to ground is the best way to verify it though.

Lets see what happens on the next test though.

 

[Faztbullet]

Re: 25HP Johnson Ignition

Check the safety switc as it makes the ground for the solenoid. Since you had carb off it could be out of adjustment, bad or if in gear/throttle advanced to far starter will not operate. If solenoid just clicks it a bad solenoid.....#63 in diagram.

 

[jasper60103]

Re: 25HP Johnson Ignition

Check the safety switc as it makes the ground for the solenoid. Since you had carb off it could be out of adjustment, bad or if in gear/throttle advanced to far starter will not operate. If solenoid just clicks it a bad solenoid.....#63 in diagram.

View attachment 119168

Hey, Faztbullet. A solid click sound from the solenoid is a good sign. It indicates that it's working. That's the sound the plunger inside contacting the terminals. A rapid clicking sound (click,click,click...) or no sound at all would be bad.

 

[CardsFan82]

Re: 25HP Johnson Ignition

Along with the electric start problem, when I try to pull start it, it doesn't do anything at all. Any ideas why?