1965 Johnson 75 hp No spark at coil

[Ross72]

I've been searching past threads for the last couple of days and have not come up with the answer I need. I picked up an old Crestliner (junk), with a decent trailer and a 1965 V4al-17s Johnson electric shift for $200.

I gave the boat away to a guy that wanted a project and kept the motor and trailer. The motor is slated for my '64 Cruiseliner that is still in the sanding stages.

Sorry, for the rambling now to the point.

There is no spark at the coil, but I have 12.44 volts. The motor turns over well, and obviously there is no spark at the plugs. This motor has the automotive style ignition.
It appears that the coil is before the distibutor, so I didn't think it could be the points or condenser. I will pick up new ones tomorrow.

The other thing I've read is about a "kill switch" somewhere on the port side of the motor and sometimes disconnecting this switch for trouble shooting purposes will achieve spark. Where is this located?

My apoligies for the length of this post, just wanted to provide as much info as possible.

Thanx for all your help.

 

[Ross72]

Re: 1965 Johnson 75 hp No spark at coil

Ok found the kill switch, will test that in the am. If the timing is not set correctly, would that cause a no spark condition? I have to order a manual for it.

It does get fuel by the way, and compression is between 85 and 90 pounds across. Compression is a little low, but it was a dry test and I'm soaking the cylinders over night, so hopefully it will be a little better tomorrow. 2 out of 3 ain't bad to start, the motor has been sitting for a little while. Also, impeller will be ordered tomorrow, unless my local dealer has it in stock.

 

[boobie]

Re: 1965 Johnson 75 hp No spark at coil

If you pull the wire out of the coil and put a jumper wire in it and crank the mtr over, do you get a spark jumping a 1/4" open air gap between the jumper wire and a ground ? If not, you have points/condensor probs. If you do you have dist cap or rotor probs.

 

[Ross72]

Re: 1965 Johnson 75 hp No spark at coil

Boobie, thanks for the reply. There is no spark at all coming out of the coil. I think I have distributor cap and rotor in the shop. Points and condensor are easy enough to swap out.

 

[Willyclay]

Re: 1965 Johnson 75 hp No spark at coil

I have to order a manual for it.

The link below will get you to a free online public library that has lots of manuals saved in pdf format. They have one that covers your motor. While it is not as complete as a "factory" manual, it does have information that you might find helpful to perform routine maintenance items and maybe even some heavier maintenance. I used this same manual with my 1962 Johnson 75 for over ten years and it served me well.

http://forums.iboats.com/showthread.php?t=393281

LOGIN as directed and then drill down to: Small Engine, Marine/Boat Motors, Evinrude/Johnson, Outboard 4-cylinder 50-85 HP (1958-1968) and Condensed Service Data.

Good luck with that great old motor!

 

[Ross72]

Re: 1965 Johnson 75 hp No spark at coil

Willyclay thanks so much for the link. I saw it once on twice before put haven't been able to find it for quite a while. We got 2" of snow last night, have to wait a couple of hours for it melt before I can get started.

 

[Ross72]

Re: 1965 Johnson 75 hp No spark at coil

It's alive!!! The points were corroded and gapped at .028", the condensor appeared to be shot. Cleaned up the cap, rotor button and points with some emory cloth re-installed points, gapped at .020" sprayed a little premix and she fired up.


Got to looking at the carb and all the adjustments are different both high speed needles are several turns apart as is the slow speed. Have to re-set carb, definetly clean it and maybe rebuild. All in all very happy.

Here are a couple pics of it running. Thanks for your help.

 

[Willyclay]

Re: 1965 Johnson 75 hp No spark at coil

It's alive!!!

Attaboy! They do not die of natural causes, they have to be murdered. FYI, if your carb has both HS and LS adjustment knobs, then it sounds like some PO has installed an early model (1958 & 1959) carb. Your model should have fixed HS jets with LS adjustment knobs only. Good luck!

 

[Ross72]

Re: 1965 Johnson 75 hp No spark at coil

Willyclay you were right the HS are fixed and have a small gasket. The one on the starboard side was unscrewed about half an inch. The LS were 2-1/2 turns apart. Gonna pull the carb today and clean her up. There are a couple of homemade wiring repairs here and there, so I'm gonna re-wire what's needed unless I can find a donor harness.

The neighbor thought my house was on fire. She came running out yelling "Where's the fire! Where's the fire!", thenshe she's the motor running and starts laughing and says oops. I was running at 16 to 1 just to get some lube in her and she was smoking up a storm.

 

[Willyclay]

Re: 1965 Johnson 75 hp No spark at coil

Gonna pull the carb today and clean her up.

FYI, there is a "special tool" recommended to re-center the high-speed spray nozzles in the carb throats. While many owners probably successfully do without this device, you might just want to leave the nozzles alone other than tightening the screws. Also, the "special tool" is not just an obscure tool that OMC called "special". It is a one-of-a-kind machined device that only does this one thing. Good luck!

 

[Ross72]

Re: 1965 Johnson 75 hp No spark at coil

Time for an update. Cleaned the carbs and ran good for a while, now won't start. There is no spark or power at the coil. I believe it has something to do with the wiring, it's in very poor shape. Some wires are missing most of their insulation and some are very detierated (sp?). Going to do some re-wiring.

Is there a source for a complete engine wiring harness? I've looked but haven't been able to find much. Also, would it be cheaper to rewire it from scratch?

On a positive note it shifts very nicely into forward and reverse. That was really my main concern.

 

[Ross72]

Re: 1965 Johnson 75 hp No spark at coil

I'm such a dumb *****. I looked at the iboats store and gee there's the harness, unfortunately out of stock. Will keep searching.

 

[boobie]

Re: 1965 Johnson 75 hp No spark at coil

Just for the heck of it take a jumper wire and run it from the battery side of the starter solenoid and to the positive side of the coil and see if spark returns.

 

[Ross72]

Re: 1965 Johnson 75 hp No spark at coil

Tried the jumper wire and got voltage, but no spark. So, I broke down and rewired the vast majority of the internal engine harnesss. I should have taken some pics, it was a real mess.

As of now, there is no spark, but on the bright side the starter turns considerably faster. I didn't rewire any grounds, but will do that over the weekend. I did check them and they are all tight and clean. I don't have a complete grasp of 12 volt systems but am definetely starting to learn.

One more question. What is the function of the capacitor? It kinda looks like a condensor, but I don't know what it's for. Also, could this be contributing to the problem?