Johnson 20

[Merrill]

I have a Mod 20RL-69D, Serial # J3116695 Johnson motor that I just got from my father in law. It needed some minor work performed which I did, now I would like to get it running. On the rear control panel on the right side it says STOP and below that is a bunch of wires exiting a hole. Most of these wires were sniped off at 8" or so. These wires go to the starter and solinid. At one time they must have been for a dash mounted start switch. Anyway, I want to be able to start this thing but I don't know how to put power to it with all these wires. Any help would be nice. Thanks

 

[tashasdaddy]

Re: Johnson 20

going to try this again, was about to post when the power failed. your engine originally came with a rope start, looking at the diagram and brp-evinrue. the starter is and add-on. if you can post the colors of the wires we may be able to figure them out. youmay be able to start to by using jumper cables and a good batttery. 1st have the motor securely mounted. ground the motor to the neg post on the battery. with the pos cable attached to the pos post on the battery, you can touch the pos post on the starter. ( make sure it's in neutral) it may start right up. this way you can atleast see if it is getting fire to the plug wires. you can also test the compression (plugs out throttle wot) turn over 4 time each cylinder. this tells us the condition of the innards. you going to need an impeller for sure. go to the engine faq forum and read awakening a sleeping outboard. ggod luck, keep us posted. ask any thing you are doubtful about. wish i had a wiring diagram for you but the earliest i have is 1977

 

[itstippy]

Re: Johnson 20

Tashasdaddy is right - the electric start is a much-coveted add on. When the motor was built there was a pushbutton kill switch mounted in that hole under the word STOP. Push it and the motor stopped running because connection was made between two black wires coming out from under the magneto and the points were shorted out. Kills the spark. Someone took that pushbutton switch out and used the hole to route the wires for both the electric start and the kill switch. So you'll have the two skinny black wires that are for the kill switch (no connection to 12V power), another couple skinny wires to activate the starter solenoid (connection to 12V power trips the starter solenoid, so you want these on a pushbutton or key switch), a big fat red positive battery connection, and a big fat black negative battery connection. That's assuming the solenoid is mounted under the hood, not externally. Take the hood off and look over the wires - it'll be pretty obvious what goes where. There is no generator and the motor does not need a battery to run; just to turn the electric starter. It's not like a car. You can start the motor just by pulling the rope. Stop it by touching the two skinny black wires together to short out the points, or choke it to death. You don't need 12V power hooked up at all. But get that electric start rigged properly and you'll be very glad you did. Sure wish I had it.
NOTE: If the guy who did the electric start conversion went all-out he also added an electric solenoid-activated choke. You'll see this if he had the motor on a boat with a console for steering & starting & stopping the boat from the front seat. That's be another couple skinny wires, leading to a solenoid on the carb.
Follow Tashasdaddy's advice and do all the proper compression testing & maintenance items for older outboards and that old girl will run forever. Strong, powerfully, thirsty machines. Love 'em!

 

[Merrill]

Re: Johnson 20

Here's 2 shots of what I'm dealing with. I'll buy a kill switch and ignition switch tomorrow. Thanks for the help, I'll keep you posted.

 

[tashasdaddy]

Re: Johnson 20

boy, what a can of worms, i hate when people do that.

 

[OBJ]

Re: Johnson 20

OH MAN! Merrill....get the manual for sure..even if it's generic, it'll have the wiring scheme in the back.

 

[Merrill]

Re: Johnson 20

I got it to crank. So now I just need to put spark plugs in and put her in a barrel of water for the ops check. I noticed that the thermostat was missing, running without one should not be a problem right?

Also what is a motor like this worth?

 

[tashasdaddy]

Re: Johnson 20

ok now you know it will run, go to the engine faq forum(top of this page, click boating forums, the enginefaq, read awakening a sleeping outboard, will tell you everything to do and check, to but it in good operating condition. don't start it without water. if it was designed with a thermostat, put it back in, running without reduces performance and carbon builds up in the engine, i would also read 'Decarb' since it's been run without the stat, and has probably never been done. if the rest of it is as rough looking as the top picture, but you get it to run well, here $500-800 maybe more. post a couple of complete pictures. it's a good engine , fix it right, and will last another 40 years. i have a '55 15hp rude. i use every week.

 

[Merrill]

Re: Johnson 20

OK, I got a factory shop manual now. Also went through the "Waking a sleeping motor" FAQ. Might try to start it tomorrow.

I Noticed the speed control seemes to be stuck, it won't turn at all, any ideas? Keep in mind the motor was set up to operate from up front with a steering wheel and dash controls. I'll check it out again tomorrow.

 

[tashasdaddy]

Re: Johnson 20

does it still have the twist grip on the tiller control? if so follow the linkage. something may be binding. could be armature plate on top of the engine. it moves with the throttle linkage to advance the timing. some times they unhook the twist grip at the bend, and the handle could be froze up from lack of use.

 

[Merrill]

Re: Johnson 20

It's a twist grip

 

[tashasdaddy]

Re: Johnson 20

soak it in wd40 , pb blaster, etc. see if you can free it up. it's aluminum so don't put too much stress on it. take a pair of channel locks and try to work it back and forth, and watch what moves.

 

[Merrill]

Re: Johnson 20

I got it running for a while, but now it won't start, not getting any spark.

 

[Xcusme]

Re: Johnson 20

Are the 2 black wires shorted??

 

[Merrill]

Re: Johnson 20

2 skinny plack wires are hanging free and not touching anything.

 

[whywhyzed]

Re: Johnson 20

Regarding the what's it worth, just an FYI, I recently bought a 75 20HP 1 owner motor for $300 on the auction site, and it's in much nicer shape than yours cosmetically....It was an "add gas and go" motor...so fix it to use it...don't spend if you intend to sell...

 

[Xcusme]

Re: Johnson 20

2 skinny plack wires are hanging free and not touching anything.

As you probably know, the kill wires, if shorted, will kill the spark to both cylinders.......I just thought I would ask...Insulate both wires seperately until you get the other issues sorted out. You can hook them up to a SPST switch to kill the motor or to a Normally Open Momentary switch. If the kill circuit is disabled ( no switch) , you'll have to choke the motor to kill it.

 

[Merrill]

Re: Johnson 20

I'm about ready to pull the lid to check the condition of the coils and points.
Do any of you have the NAPA part #'s for these parts? When I fixed my Evinrude 40 I bought the green coils from NAPA along with the points, I'd like to do the same with this motor.
I'll do another check on the no-spark problem. When it was running it was rough, might have been hitting one only 1 cyl, would not idle good either. Any ideas on the no-spark situation before I tear into her?

 

[tashasdaddy]

Re: Johnson 20

i think your heading in the right direction.

 

[Merrill]

Re: Johnson 20

I pulled the lid and found 1 coil cracked and corroided.

I went through a like problem with mt 40 HP Evinrude. I think I can come up with the NAPA part # for the coils and points for that motor. They look to be the same as the Johnson 20 HP, are they?

The 1 bad coil explans why I was'nt getting fire to 1 cyl, not sure whats wrong with the other though.

Thanks