77 Johnson 85hp no spark

[mrandmrsalf]

I have a 77 Johnson 85hp that is hard to start from time to time. I had the motor running on the muffs yesterday but today when I tried to start it, it wouldnt. It turns over fine but will not fire. I pulled the plugs one at a time and checked for spark and none of them are firing.

Ever since I have owned this boat, the motor has always been a PITA to start first time of the day, but after that, it will run strong all day. I am almost wondering if the no spark is an intermittent issue because sometimes when it will not start, I try a few things, and it will start with no explanation. Its like it starts when it wants.

The battery is fully charged and I even cleaned all the groungs and wire terminals to the power pack and coils.

What would be the best way to troubleshoot this?


The model number is 85ETLR77S.

 

[tashasdaddy]

Re: 77 Johnson 85hp no spark

unplug the big red harness plug, this takes a bad ignition switch out of the equation. then, mount the muffs on water intake, connect hose. now with a remote starter switch, auto parts store, connect 1 wire of the switch to the top battery post on the solenoid, the other wire to the top small post, turn water on, squeeze switch, motor should turn over. CAUTION: there are only three ways to stop the motor, disconnect fuel line, choke the motor, or remove all plug wires. DO NOT rev the motor higher than 1500 rpms. it can cause a run away motor that cannot be stopped, other than disconnecting fuel source, but in the mean time, may throw a rod, etc.

if that does not work >>> http://www.boatpartstore.com/page30.asp

 

[mrandmrsalf]

Re: 77 Johnson 85hp no spark

Heres an update... I went out first thing this morning and pulled a plug and still got no spark. Gave up on the idea of going fishing so I took the wife out to breakfast. On the way back stopped by Auto Zone and bought a gear puller to pull the fly wheel and said what the heck... I'll try it one more time. Wouldnt you know it, the dang thing started right up. The only thing I did was turn the steering wheel so now Im wondering if I might have a short in the main harness going into the motor.

Is there anyway to check for a short in this cable? I know intermittent problems are next to impossible figure out.

I am open to any ideas, but I think I might be on to something with the main harness.

 

[tashasdaddy]

Re: 77 Johnson 85hp no spark

the post i just posted takes the harness and all of the controls out of the circuit. the only way i know is to do readings on each wire.

 

[mrandmrsalf]

Re: 77 Johnson 85hp no spark

I read that in your post but it did not click with me. I will try that. I still need to find a remote starter switch...Auto Zone said they didnt have any this morning when I was there. I will keep looking though.

Thanks

 

[mrandmrsalf]

Re: 77 Johnson 85hp no spark

Is it possible for the power pack to be intermittent or is it one of those things that either works or it dosent? I ask that because I just went out and tried to start it and I got nothing...didnt even turn over. I wiggled my harness around going into the motor...nothing. Then I took my controls apart and checked the switch wiring and cleaned all the terminals...nothing. Cleaned all the terminals in the power pack...nothing. Then I unbolted the power pack, leaving all the wires connected, put it back on and it started right up.

I absolutely HATE intermittent electrical problems. They are a pain. I refuse to take this thing to a shop as I am very mechanically inclined but just need a little guidance from time to time.

 

[Daviet]

Re: 77 Johnson 85hp no spark

Electrical systems can cause you to pull your hair out at times. You might want to remove and clean all grounds on the engine and make sure the ground strap on the power pack is clean and tight on both ends.

 

[mrandmrsalf]

Re: 77 Johnson 85hp no spark

Yep, thought of that too. A couple of weeks ago, I disconnected every terminal I could find on the motor and on the battery and cleaned them. The only ones I did not do at that time was the switch but I did that one today.