1978 35hp Evinrude stuck.

[lindeman]

My new to me 78 Evinrude has started to run at about half power. Innitially, the problem existed after a cold start. It would not develop full power for a minute, and then something would "click" and the motor ran great at wot. It was not a gradual change. Without touching the throttle, the engine would suddenly start running full. Over the past month, the innitial period of half power has gotten longer before the engine clicked into full power. Yesterday, it took 30 minutes for the full power to click in. After 1 minute of running correctly at wot, I throttled down and attempted to throttle up again. Half power. Couldn't get the engine to click back into full power.

I had the carb professionally cleaned and rebuilt a few weeks ago for other reasons. It seems that something is "sticking."

Please help.

thanks,
Lindeman

 

[jasper60103]

Re: 1978 35hp Evinrude stuck.

Sounds like you're running on one cylinder when not a full power. I would do a spark test.

 

[boobie]

Re: 1978 35hp Evinrude stuck.

Sounds like an ignition prob. Could be coil or pack. Have you replaced the spark plugs ??

 

[lindeman]

Re: 1978 35hp Evinrude stuck.

Thanks. I believe you have sent me in the right direction. Replaced sparkplugs with no change. Performed spark test. One cylinder is getting no spark. Light brown wires look good. Two black wires are old, insulation disintegrating. But everything looks intact. What is the next step?

thanks,
Lindeman

 

[boobie]

Re: 1978 35hp Evinrude stuck.

You might try swapping coils to see if if the no spark follows the coil.

 

[lindeman]

Re: 1978 35hp Evinrude stuck.

Will do. As soon as I figure out what a coil is.

Lindeman

 

[lindeman]

Re: 1978 35hp Evinrude stuck.

So I've id'd the coils. It appears to me that swapping the coils will require cutting wires and using butt connectors to crimp back together. Does this sound right?

 

[AlTn]

Re: 1978 35hp Evinrude stuck.

use a little rubbing alcohol as a lubricant then push the male connector ends out of the amphenol plugs and swap them...I've used the head of a large finishing nail to do this, but anything that won't damage the pin will work. Note the plug connectors have A, B, C, etc molded around the plug holes. Each component, coils for example, needs to plug into the lettered hole for it,ie; A. may be the top coil, B. the lower...anyway, mark your coils for top or bottom then follow the wire to the plug and note the lettered position it goes back to. The coil wires must go back to their proper place in the plug or you'll have reversed the firing order which is Top - Bottom. If the powerrpack to coil wires have a tracer in them..the blue tracer is the Top , and the Green is the Bottom...< Blue Sky, Geen Grass >

 

[boobie]

Re: 1978 35hp Evinrude stuck.

If the problem stays the same after you do the swapping, you may have a bad power pack.

 

[lindeman]

Re: 1978 35hp Evinrude stuck.

It is just as you describe. Switched the coils, and the spark follows the wire, meaning it's a power pack issue, right? Any reason not to track down another power pack at this point? I went ahead and took it off the motor.

 

[AlTn]

Re: 1978 35hp Evinrude stuck.

just to be certain...which ever, top or bottom cylinder,that wasn't sparking before the swap still isn't sparking regardless which coil is in that position?..then, yes, the powerpack is the most likely suspect

 

[lindeman]

Re: 1978 35hp Evinrude stuck.

I don't follow. When I switched the wires supplying juice to the coils, the spark switched to the other cylinder. My brain tells me one wire is sending juice and the other not. Therefore, the problem is upstream of the coils, thus the power pack. Right? Said another way, the wiring switch I made is between the power pack and the coils.

 

[boobie]

Re: 1978 35hp Evinrude stuck.

Right. sounds like a pack.

 

[lindeman]

Re: 1978 35hp Evinrude stuck.

I replaced the power pack. The engine is happy, fixed, running great.

Thank you so much for your accurate help and guidance. I'm a happy guy.

Lindeman

 

[jasper60103]

Re: 1978 35hp Evinrude stuck.

I replaced the power pack. The engine is happy, fixed, running great.

Thank you so much for your accurate help and guidance. I'm a happy guy.

Lindeman

Glad to hear. Thanks for the update.