1964 Evinrude 40 HP Big Twin

1819suny

Cadet
Joined
Jun 26, 2007
Messages
13
Well, I am back. I have a 1964 Evinrude 40 HP Big Twin. Runs fine at low speeds, cuts back and sometimes stalls after running at high speed for a very short while. I have replaced the fuel pump, fuel lines, plugs, condensor, and points. I have checked inside the gas tank and all is fine. A metal connection goes into the gas tank. There is a screen on the end of it and it is wide open and looks fine. We have noticed air bubbles in the fuel line. They are there at low speeds as well and don't seem to effect the way it runs at low speeds. Does anyone have any further ideas. I appreciate any help. Thanks, Jim
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: 1964 Evinrude 40 HP Big Twin

How do you know there are bubbles in the line? You got some of that plastic hose on it? That stuff is great for causing worry. If you had black hose you wouldn't see it and wouldn't be a'worrying. And you will never get it to go away, so quit looking.

Anyhow, have you checked the high speed orfice jet in the bottom of the carburetor? It is deep in the hole behind the hex drain plug and takes a special screwdriver to get it out. It must be absolutely CLEAN or it won't run correctly at high speed. Absolutely no gum, coating, dirt or anything allowed in there.

The tool:
http://i155.photobucket.com/albums/s311/frankr_photos/FixedJetScrewdriver2.jpg?t=1184550182
 

1819suny

Cadet
Joined
Jun 26, 2007
Messages
13
Re: 1964 Evinrude 40 HP Big Twin

Thanks Frank, I will give your idea a try. Thanks for posting pictures of the screw drivers. Jim 1819suny;)
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 1964 Evinrude 40 HP Big Twin

have you check spark, when it quits, you did not mention coils, they get hot and sometimes fail.
 

BillP

Captain
Joined
Aug 10, 2002
Messages
3,290
Re: 1964 Evinrude 40 HP Big Twin

One of the early signs of coils going bad is they work cold and break down when hot. At high speed it acts quickly like you pulled a spark plug wire off...then when cool everything is fine again.

Bill P.
 
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