'94 60 HP Johnson wont rev up in gear - video

[IDFISHER]

I took my boat out for the first time this year and things did not run smoothly. It starts up and idles great. When I shift it into gear at low speed it moves along just fine. But when I pin the throttle it barely wants to move along. When I put it back into neutral and kick up the throttle lever it revs up better than when it's in gear but still not as good as it should be (in my opinion). Certainly seems like a fuel issue but I could be wrong.

I took a video of it hoping that would help diagnose it. https://www.youtube.com/watch?v=_eAUjYcir8E

 

[IDFISHER]

Some additional info....I took the carbs apart today and gave then a thorough cleaning even though they looked in great shape. I did notice that the screw at the top of the each carb in the front was loose and allowing fuel to leak out so i tightened those. Would that loose screw cause problems?

I fired it up in the driveway on the muffs and it started and idled fine and it would rev up good in idle and in gear. What would cause a motor not to rev up in the water under a load but run fine out of the water?

 

[racerone]

In gear on the hose is still neutral as the prop in air does not do any work.-----Start with a compression test on that motor.---Post your numbers.---Then check for spark on all 3 leads.---Spark must jump a gap of 3/8" or more to be good.

 

[IDFISHER]

Update...pressure is 90 psi on all 3 cylinders. Isn't that a bit low? Spark on 2 top cylinders is good but VERY weak and intermittent on the bottom lead. Swapped some leads around and got the same result. Does that mean it's a coil issue?

 

[racerone]

How can spark be " good but VERY weak " ?----Does spark jump a gap of 7/16" , yes or no ?

 

[IDFISHER]

Sorry, I worded that poorly. The top two plugs/leads are good. The bottom lead has a VERY weak and intermittent spark.