Johnson 130 hp wont run right

[Hammer12b]

I have a 1998 Johnson 130 that I bought a month to so ago. It had a small hiccup like miss in it when I got it. I thought water or new plugs but it has gotten worse to the point of where it lumbers to pull itself into plane and then won’t get past 20-25 mph. It will labor along and then all of a sudden start running right and rocket out of the water to about 40 mph! If you’re not holding on, it’ll throw you out of the boat! I took it to the shop and he took about a pint and a half of water out of the filter, cleaned the carbs and put K100 in the fuel. I changed the plugs and it ran for about a day then right back to running badly. Took it back to him. He’s checked the rectifier, the plugs, the carbs and put it back in the water 3 times and the same result. It’s getting fuel, spark and compression but something won’t let it come to full power. Any advise?

 

[racerone]

Have him look into issues with crankcase compression.-----Another test is to remove one plug wire at a time when idling.----The RPM should change the same each time.