76 55hp Won't Run With Lid On / Prop Question

[neckermann]

I did try and search the threads, but I didn't find anything... Maybe I searched for the wrong words.. Sorry if this information could be found elsewhere.

Ok so I have a 1976 Evinrude 55643E 55HP. I bought it this year. The first time I put it in the water it wouldn't stay running. I found one carb was all gumbed up and cleaned it boat ran fine for 2 days.

It sat for a couple of weeks. I went to go out in it and it seemed real doggy, it took forever to get on plane, and ran like crap.

The next day I went to take it out by myself again and it didn't seem right again. So I take the lid off and pow the boat runs great! I took it out with the lid off the motor and it ran good for 5 gal of gas worth. Took the lid apart because I thought the air vent was clogged or something. Cleaned it all the way out. Soon as I put the lid back on the boat wants to stall out.

There was some foam on the inside that was kind of hanging down so I ripped it off. There should be nothing in the way. Is there something I could be pinching or something? I looked I didn't see anything.


Could I be doing something wrong?? Is there something I am missing? I don't know why it ran good the first couple of days out and now it will only run good if the lid is off. It just seems like it is starving for air. I tried adjusting the air mixture screws, but it didn't seem to do anything but make it run worse, so I put it back to where it was.

I also need a new prop for this motor and I need some suggestions as to what I should get, and where I can find the cheapest one. I would like to take my 5/7 year old tubing in it, and if you guys think the boat and motor are up to it maybe an adult.


Boat: 1976 17' Sea Star
Engine: 1976 Evinrude 55hp 55643e
Current Prop: 11-3/4 x 17


Nicholas

 

[jay_merrill]

Re: 76 55hp Won't Run With Lid On / Prop Question

I can think of a couple of possibilities.

First, look for an exhaust leak. If the engine is breathing exhaust that is leaking from the powerhead base, the exhaust cover on the port side of the powerhead, etc., it isn't going to run well with the cover on. When you take the cover off and the motor has acess to clean air, it will run fine.

You may also have a loose wire somewhere. It might be a spark plug wire, the wire that goes from the powerpack to a coil, etc. If the cover is hitting that when installed, you might be running on one cylinder as a result.

 

[neckermann]

Re: 76 55hp Won't Run With Lid On / Prop Question

Jay,

I will give those a try. Thanks for the info.

Nicholas