1978 Evinrude 35hp Cutting Out At Full Throttle

[BullSlamma]

Hey guys,
I have a 78 35hp RUde that is cutting in and out at full throttle. It won't shut down if you have it even at 90%, it's just when it's open all the way and it takes about 10 seconds before it starts to cut out. It also will idle really good but all of a sudden at low idle will just stop. Turn the key and she fires right back up. I noticed the other day that one cylinder wasn't firing and when I messed with the coil/power pack wires a little it came right back and has ran on both cylinders since. I am wondering if the powerpack could be going out and is starting to foul up when the motor is at high RPM's and really low idle? Any ideas? Thanks a lot!

 

[tashasdaddy]

Re: 1978 Evinrude 35hp Cutting Out At Full Throttle

dirty corroded connections, possibly ground on coils. when were the carbs last cleaned and rebuilt? new fuel lines.

read this: http://forums.iboats.com/showthread.php?t=330129

 

[BullSlamma]

Re: 1978 Evinrude 35hp Cutting Out At Full Throttle

I just bought the motor about a week ago actually. The powerpack actually looks new, the ground on the coil wires makes sense. I replaced my gas tank but (Ahah.....) didn't replace my gas line and bulb. I probably should pull the carb and clean/rebuild it. I would suspect that hasn't been done in a long time. Could the carbs be gummed or trashed? The high end jet maybe? Thanks for the response.

 

[BullSlamma]

Re: 1978 Evinrude 35hp Cutting Out At Full Throttle

OK, just took apart carb and everything looked good inside it. It was very clean, I did however find a strand of plastic that was lodged down inside the high jet. I was able to pull it all the way out, I am going to assume that was what was causing me to shut down on the high revs. Also, when I started to take the carb off the carb was loose from the manifold....like you could actually move it around and it would be easy to see how that could have been a problem. So tomorrow off I go to buy a new carb kit and fuel line. Meanwhile I have the carb sitting in a bath of carb cleaner tonight. Tomorrow afternoon when I get off work I plan on blowing out the carb with compressed are before I rebuild. I bought the motor from a man who lived in AL and he said that he has never ran an ethanol mix fuel though the motor and that the hoses in the motor should be fine. I think this might have been the problem. I also sprayed some cleaner in the plug wires and coil ground connections and tried to get them as clean as I could. I am hoping this will fix the motor because other than that. It's rock solid. I will post when I get to my next stage to update. Thanks for the help!

 

[bouttime007]

Re: 1978 Evinrude 35hp Cutting Out At Full Throttle

Sounds like you are on the right path.

 

[BullSlamma]

Re: 1978 Evinrude 35hp Cutting Out At Full Throttle

Well got everything rebuilt and the new fuel lines on. I fired it off and it ran fine for a second, then started running rough, really rough. I pulled the top spark plug wire and no change in the sound of the motor. I put it back on and started to jiggle the ground wire to the coil and the motor started to rev higher for a sec and cut in and out. The motor definitely made different sounds as I jiggled that coil wire. I am going to guess the coil is shot. This makes sense because it is the original coil that came with the motor. Does this sound like it could be my problem?
Thanks guys,