Question about boat performance

I purchased a boat about a year ago and it ran great the first few times i took it out. Shortly after I had to have the stator and rectifiers replaced, while doing that I went ahead and had the trigger done as well. The boat would run great at idle and great on the top end but would struggle to get on plane. I could get full rpm's out of it 5500 1998 Merc 150, but it would take 20 seconds or so to get on plane. I put it back in the shop and the guy found a small vacume leak and repaired that and replaced the spark plugs, but acording to him the rest of the motor was like new. Compression even, good spark on all cylinders etc. The boat would jump onto plane when I first got it and now it is acting like I have 20 grown men in the boat with me. I checked the hub to make sure it isnt spun but it appears to be in great condition. The only other advise the mechanic would give me was to drain the gas and see if i got a bad batch of gas.

1998 Challenger 19' center console 150hp mercury Prop 14.25" 21pitch 3 blade.

Any advise would be great I have had the boat in the shop just about the entire summer and I would like to be able to take the kids fishing at some point.

Replace all of the fuel lines, change the manual fuel pump diaphragms and clean the fuel tank pickup tube. Is this a carb or an injected motor? What was the compression?

It is a carbureted engine and not sure if the compression just that the mechanic said all cylinders were good and even.

If it doesn`t have 110 or better that motor will not have good power. Just went through this on a 2004 XR6. It was not responding to anything I did to make it get on plane like it use to. Pulled it down and put new rings in it. Now has 120 to 125 on all cylinders and runs great again.

I will check and see what it has. I appreciate your help.

When I had the problem it was an electronic issue, maybe a coil, don't remember. No power but once you got on plane it would get on speed. Couldn't tell at idle because my engine only idles on two cylinders and the other two kick in at a certain RPM. Maybe they need to check the electronics some more.

Thanks for the input. I replaced the coils the week I purchased the boat. I will double check them but the ones on there are less than a year old.