Johnson 15hp no power

[scruffy63]

I have a 79 Johnson 15hp that has 110 lbs compression both cyl's, new coils & powerpack. Has great spark, carburetor has been cleaned and float has been set per gauge, new fuel pump, starts easy and idles great but on boat it lacks speed as others I have worked on. I have tried various settings on trim. what am I missing?

 

[racerone]

Broken reed valve ?

 

[scruffy63]

That could be as it was not running foe years before I got it. Will check.

 

[Boobie]

Do a cylinder drop test on it to see if it's running on both cylinders.

 

[scruffy63]

How is that done, both cyl's have 120lbs. and spark is good

 

[Boobie]

Pull one spark plug wire at a time when you have it running about 2000 rpm and see if they drop the same.

 

[scruffy63]

Ok will do it.