1963 40 hp johnson,

[gypsy121761]

My 63 johnson outboard, is has plenty of power in nuetral, then in forward gear wide open act like its running on 1 cylinder. Anybody have any ideas at what going on there?Thanks Jess

 

[tx1961whaler]

Re: 1963 40 hp johnson,

Yes.
It is probably running on 1 cylinder. It will run on one cylinder quite nicely in neutral.
Check the compression first (around 100 psi, but more important to be even across the two cylinders).
Then check the spark using a spark tester. Should jump a 1/4" gap.

 

[F_R]

Re: 1963 40 hp johnson,

Agreeing with tx, but don't ignore the simplest of all possibilities----bad spark plug????

 

[roger56]

Re: 1963 40 hp johnson,

got the same problem with my 59 Johnson. Trying to figure it out