1969 Johnson 40HP Wiring Rebuild

[newhamburgboating]

Hey Folks,

I appreciate any help well in advance, I know this forum will get me where i need to be. Just a matter of time and who wants to be the hero

So some back story, picked this guy up in rough condition, new to boats, and figured i would jump in head first. Last year I had it running for about 60 hours. It died on my last day at the cottage for the season so no harm no fowl. Now here we are in the spring and it's time to get it going again.

General observation was no spark on the bottom cylinder. it would start, but any throttle would flood and stall.

Looking at the wiring it didn't surprise me, previous owners must have had an all you can shred squirrel buffet in their barn.

Now, the wires when i got it were shredded and had already been replaced once, and not with factory coloring. I just replaced one for one at the same length.

Currently I have 5 wires on the runaway switch(four to the post, one to the ground that runs up to a switch looking device that contacts the aperture plate when under throttle). I do not believe this to be stock.

The automatic choke never worked, but that's fine with me, I can reach the choke and key at the same time.

I already replaced the magnetos, condensers, points, wires and boots on the plugs.

what I would like to do is get the wiring sorted back out, I am positive some of these are connected to the wrong spots, and some not even needed are connected to stuff they have no business connecting too.

I have spent the last three days looking for a picture of the engine clear enough to sort them all out. found a few things that have helped, but alas, still have questions.

/end rant

First question. I have two wires that come down from the aperture plate (i think they are the wires that comes up under the magneto and connect to the points) that are both connected to the middle post of the run away switch. this doesn't sound right to me.

I haven't posted enough to put up pictures yet.

Thanks!,
Steve

 

[lindy46]

Re: 1969 Johnson 40HP Wiring Rebuild

Only one kill wire should be connected to the cut-out switch, and then should go on to one of the "M" terminals on the ignition switch. The other kill wire should go directly to the other "M" terminal. If they are both connected together, they will ground out the points and you'll have no spark.

 

[HighTrim]

Re: 1969 Johnson 40HP Wiring Rebuild

Hey Steve, whereabout are you from?

Here is something that will get you close.

As stated, only 1 lead to the cutout, then onto the M terminal. The other black lead direct to the M terminal

 

[newhamburgboating]

Re: 1969 Johnson 40HP Wiring Rebuild

Thanks Lindy and HighTrim,

Late last night I was able to straighten a few of these out. the M contacts makes sense. I will switch that as soon as it dries up a bit outside.

Another question, I have a wire that runs right into the back of the engine block, it goes into a grommet about a inch to left of the bottom cylinder. I'm taking a wild guess this is the tachometer? or perhaps a temperature switch?

HighTrim, well I'm about 15 minutes Southwest of Kitchener. The Nith River is pretty much my backyard.

I now have spark on both plugs! looking forward to correcting the rest of these wires and then testing it out!

Thanks,
Steve

 

[newhamburgboating]

Re: 1969 Johnson 40HP Wiring Rebuild

OK, I remade the picture you posted, as how I believe it should be on mine (no generator kit)

This is what i will be changing it to later today.

One final question, I noticed last night that the ground post on the cut off switch is not in fact grounded through the switch. should I be grounding this on my own with another wire?

 

[lindy46]

Re: 1969 Johnson 40HP Wiring Rebuild

The side post on the cut-out switch only acts as a connection point for the starter solenoid and the neutral safety switch. When the motor is in neutral, the safety switch grounds the starter solenoid to the engine block and the starter fires. In any other position, the solenoid is not grounded to the block and the starter wont fire.

 

[HighTrim]

Re: 1969 Johnson 40HP Wiring Rebuild

The wire beside the bottom plug is a temperature switch.

 

[newhamburgboating]

Re: 1969 Johnson 40HP Wiring Rebuild

Thanks Chris, I haven't come across a temperature switch in my travels, is the required? right now i have it just taped off.

 

[newhamburgboating]

Re: 1969 Johnson 40HP Wiring Rebuild

OK, so all the wiring is done, starter kicks and everything looks good but now i do not have any spark on both cylinders. Last night I did by using the pull rope. I disconnected both the M wires, as I think i remember hearing that's a good test.

Any advice on steps to take to trace this down? Like I said I just did the Coils, Points and Condensers on Thursday.

 

[HighTrim]

Re: 1969 Johnson 40HP Wiring Rebuild

So you have spark if you disconnect the knife connections that go to the mag plate?

 

[newhamburgboating]

Re: 1969 Johnson 40HP Wiring Rebuild

sorry, no i do not.

 

[newhamburgboating]

Re: 1969 Johnson 40HP Wiring Rebuild

Update: I put my old condensers back on, and noticed a spark on both plugs, put it all back together, started it up with the ignition and it ran for about 30 seconds then died, now will not fire, pulled the plugs, no spark again, what gives?

 

[HighTrim]

Re: 1969 Johnson 40HP Wiring Rebuild

What are you torquing the flywheel to...was the key ok?

 

[newhamburgboating]

Re: 1969 Johnson 40HP Wiring Rebuild

flywheel is just by hand, once tight, 1/8th turn, checked the key looks ok, i know it is certainly spinning the shaft with the flywheel because i can put it in gear and rotate it seeing the prop move.

 

[HighTrim]

Re: 1969 Johnson 40HP Wiring Rebuild

There is your problem. That flywheel needs to be torqued, and ALOT. 100 ft lbs

 

[newhamburgboating]

Re: 1969 Johnson 40HP Wiring Rebuild

Thanks.

i will crack it down even harder and see if i can see some spark. don't have easy access to a torque wrench.

 

[newhamburgboating]

Re: 1969 Johnson 40HP Wiring Rebuild

ok, so i got another 1/4 turn out of it with 2 foot pvc pipe on the end of my wrench. all i had and it wouldnt go further. still no spark. i put my voltmeter into the plug boot and registered a couple readings on it. couldn't tell really what they were but it did at one point max out my meter.

 

[newhamburgboating]

Re: 1969 Johnson 40HP Wiring Rebuild

I'm not sure sure if this is correct, but i will describe what i noticed.

As i read earlier, when dealing with a no spark issue you want to disconnect both M wires (the two that come down from under the coils) as a test. If you then get spark, it means the kill switch is grounding. the motor should spark and run at this point. leaving you to figure out the wiring issue with those two wires.

I read somewhere saying that these two wires if connected to each other would prevent the motor from starting as well.

I have disconnected mine, and with an multimeter i have determined that they have continuity between them. is this to be expected or is this my reason for no spark?

I'm not really clear on how the points send the electricity. when the points are open i am seeing continuity on side of the point with my multimeter, this seems wrong. logic being i should not have anything when they are open, and then when they are closed, i should thus sending the electricity.

 

[euphomus]

Re: 1969 Johnson 40HP Wiring Rebuild

Hey Steve, whereabout are you from?

Here is something that will get you close.

As stated, only 1 lead to the cutout, then onto the M terminal. The other black lead direct to the M terminal

View attachment 197391

Great wiring diagram! Exactly what I needed for my 67 electramatic

 

[newhamburgboating]

Re: 1969 Johnson 40HP Wiring Rebuild

There is your problem. That flywheel needs to be torqued, and ALOT. 100 ft lbs

Well, I got it! Friday night i replaced the condensers, adjusted the timing, and freshened up the gas, not sure which of the three was the specific cause, but it starts pretty easy and sounds great, little rough on the low end Idle, but 'm goign to pickup some J6C champion plugs and rebuild the carb when the parts are in later in the week.

THANK YOU to everyone who assisted, it was frustrating at times, but I am way better off now then if i just took it in to get fixed.