1960 Johnson 40Hp.

[sjaarda]

Got a johnson 40 for my 14ft aluminum runabout. It replaced a 28Hp. I cannot get the 40 to plane the boat out. Its like the motor will not rev up fully. It has very limited power. I replaced all the fuel and vacuum lines, cleaned and adjusted the carb to factory settings, and compressioned checked the cylinders, (both at 130psi.) The motor idles great and when its in neutral it seems to rev much higher than in gear.
My prop is not chewed up. My lower unit leaks oil but I don't see where that would affect it. Could it be my linkage.
Any help?

 

[steelespike]

Re: 1960 Johnson 40Hp.

See if the carb is opening all the way.Have you tried adjusting the high speed
needle valve.
You may have a dead cylinder.Unhook one plug at a time and see if it runs.
My guess is on one of the cylinders it won't run.If the coils haven't been replaced they will most likely need replaceing.

 

[freddyray21]

Re: 1960 Johnson 40Hp.

agree it is probably running on one cylinder. I have the same motor and my wife skis behind it. Check the coils and replace.