replacing coils on 77 johnson 35 hp

[Jeff74]

Hello Guys,

I'm planning to replace the coils on my 77 Johnson 35 hp. It looks pretty basic, unbolt, unplug the old ones, bolt back in and plug back in the new ones. Any pitfalls I should be aware of? Thanks!-Jeff

 

[Jeff74]

Re: replacing coils on 77 johnson 35 hp

I meant to say I'm planning to replace the power packs. My engine sometimes stalls at mid-throttle. Usually, this results in the motor quitting. Good idle, good no-wake speed, good top end. Replaced the fuel filter and it does look like it's getting fuel. Thought I'd move on to electrical. One of the power packs has some corrosion, so I thought it might be due for replacement.

 

[boobie]

Re: replacing coils on 77 johnson 35 hp

Power packs?? It only has 1 power pack but 2 coils. Please explain????

 

[Jeff74]

Re: replacing coils on 77 johnson 35 hp

I got it wrong. I did mean the coils. The bottom coil has rust damage. After reading through the forum it sounds like this could be the problem causing my engine to stall at mid-throttle. It purrs along fine at trolling speed and runs great at WOT, only has trouble in the mid-range. I'll try to be more accurate with my future posts. Thanks for your help.

 

[Joe Reeves]

Re: replacing coils on 77 johnson 35 hp

If "stalls mid throttle" means that the engine dies out when throttle is applied.... clean the carburetor and manually clean the brass high speed jet that's located in the bottom center portion of the float chamber.

 

[Jeff74]

Re: replacing coils on 77 johnson 35 hp

Hello Joe,

here's a better description of what's happening: runs well out of the no-wake zone, throttles up fine through the whole range all the way to WOT. At this point, when the engine is still relatively cold, it runs fine in the mid-range. After running WOT for a while, then throttling back, it does well in no-wake speeds, but then if I throttle to mid-range, it runs fine for about a minute, then begins to stall. It doesn't always die when it stalls, but ultimately does. When this starts happening, I restart the engine, and again it runs fine in no-wake speeds and high end, but mid-range has problems. It doesn't strike me as a fuel delivery problem as I have replaced the inline filter, cleaned the carb, checked that the tank vent is open and can start it after it dies on the first crank without re-priming the bulb.

 

[Joe Reeves]

Re: replacing coils on 77 johnson 35 hp

If the fuel primer bulb has a tendency to flatten out, such as being compressed, that would indicate a fuel restriction. Usually a sticking anti siphon valve at the fuel tank.

If the above does not take place, have someone constantly pump the fuel primer bulb (acting as a manual fuel pump)...... if this corrects the problem, suspect a minor fuel/air leak at some point between the fuel pump and the fuel supply, or a failing fuel pump.

 

[Jeff74]

Re: replacing coils on 77 johnson 35 hp

I'll give it a try. Thanks, Joe.