Yamaha 30hp won't accelerate in gear. More added

[Okeswamp boater]

I have a Yamaha 1988 30hp oil injected, elec start engine on a 15' Lowes Prowler pro. I have had this since 1990 and it has been pretty problem free. I let it set up too long once before and had to clean the carbs. The boat ran fine last summer but when I took it out this year it idled fine but would not put the boat on plane. I took the carbs apart and cleaned them but I didn't find much in them. I replaced the gas with new gas and changed the plugs. Took it back to the river today and it still won't plane the boat. It cranks fine, idles fine, even revs fine in neutral. I sprayed a burst of WD-40 in each carb at WOT while my son drove the boat just to see if maybe one carb wasn't working properly, but no change in sound or power. By the time I left the river it wouldn't even stay running in gear. It would slowly start to die when put in gear and wouldn't rev at all. I checked the compression and I get about 105-110 on all three cylinders. What could it be?

Did more tests. I pulled the plug wires off while the engine was running and it dies down a bit when 2 and 3 are pulled, but no change when 1 is pulled. I changed the coil packs and spark plugs on #2 and #1 and it still is the #1 cylinder that has no change. So I figure it has to be the carb. I pulled the carb and cleaned it again and everything looks fine. What is the next thing I need to check?