'78 Evinrude 85hp

[iluvgear]

My '78 Evinrude 85hp is running poorly. It will not run at top rpms. Feels like it is bogging down. Occasionally it will surge and run smoothly. My suspicion is I am loosing spark to one cylinder. New fuel line/bulb, clean filter screen, and when it surges the power is instant, faster than throttle response. With the engine idling I tried wiggling each spark plug boot to ensure a solid connection. This had no effect on the engine, but the lower port side cylinder send a good shock up my arm. I did not see any arching. Could this be my problem? Thanks in advance for any advice.

 

[Backlash]

Re: '78 Evinrude 85hp

Hey iluvgear (I do too!), It might be worth a try to run the engine, cover off, in darkness to check for arcing. Based on your description of the symptoms, it does sound like an electrical problem rather than a fuel related issue. Could be something easy but then again............Let us know what you find out. Good Luck.

 

[ridiver]

Re: '78 Evinrude 85hp

Hmmm, our 1978 85 Hp Evinrude did the same thing. There was a loose wire. (we knew because it had been taped in place by a previous owner) We just pushed the wire back it for that cylinder, started getting a spark again , and off we were...<br /><br /><br />f<br /><br />

 

[pstewart]

Re: '78 Evinrude 85hp

I had a similar problem with my motor. The inside cover is covered with foam which is slowly falling apart into dust. I took the carbs off and cleaned them out. Turns out these particles were getting into the carb and clogging it up. Sometimes it would run OK, other times it wouldn't. Previuos owner had no air filter on it.

 

[Mod2]

Re: '78 Evinrude 85hp

Moving to Johnson/Evinrude forum.