overheating little Evinrude motor

[knashcat]

I just bought this motor from an insurance recovery auction and am needing some help with it, please . I beleive it is a 1969 Evinrude 4hp Lightwin Yacht Twin the serial # is 4006E-E01682 can someone confirm this ? Also its overheating . Has good water pump and flow , was told maybe plugs or coil . What plugs would it take and would anyone know the proper coil that this motor should have ? and of course any other ideas of what could be causing the trouble. THANKS in advance

 

[Paul Moir]

Re: overheating little Evinrude motor

That's a 1970 Evinrude 4hp. Spark plugs are Champion J6C gapped at .030".

There are two parallel cooling passages on that engine - perhaps one is blocked. You can tell this is happening because the bypass passage remains cool but the head gets burning hot. The head is normally hot so to tell if it's too hot, dribble a little water onto it. If it sizzles it's too hot.

Have a look at my 4hp site here:
Click here

Click on the picture and it'll expand.

Plugs & coils don't cause overheating. Only lack of water flow or a blown head gasket does. But if the head even partially blows on a 4hp, it won't run.

(the 1973 4hp post is near identical! )