So when I take off and I'm about to be on plane, the engine will miss for a split second. Sometimes does it after I get on plane but never after I've been going for more than about 20 seconds. Still gets great top end speed. Checked my plugs today and 3 of the 4 were normal. 1 was extremely dry.

I would first check the carb on the dry cylinder.

Would it still run well at top end if that carb was gummed up? Or would it be more likely to be an ignition problem?

That spitting could be because of dirty idle circuit, cracked or broken reed, vacuum leak, carbon build up. I do not think it would still run good at the top end with an ignition problem. I simply thought it would be easiest to check the carb on the dry cylinder first.

I've got a carb kit ordered and on the way. Going to get a new set of plugs too.

Ran some deep creep straight through the carbs. Pulled the plugs and they looked like this. In order from 1-4 left to right.



Put in new plugs and all looked pretty dry after letting it idle for 3-4 minutes. I guess that's better than being fouled.

While it was running, I pulled the top left plug wire (dry one) and it definitely stumbled, so I know it's getting at least some gas and spark. Inspected the coils which are only about 2 years old. No cracks in the gel material. Hopefully a new carb kit will solve the issue. I still feel like that top left cylinder should be getting more gas/oil on the plug.

Actually the dryer plug looks more normal than the oil soaked ones.. let me ask, do you let your motor Idle for a bit after coming off plane, and are you premixing your oil?
I would guess that the number 3 or 4 plug is oil fouling and starts hitting when the motor is firing hard with the rpm increase.
Shine a flashlight into the spark plug hole and see if there is alot of carbon buildup on the pistons. if so get you some evinrude tuner spray..
Also start your motor on the cuffs at night and look for any spark jumping.
you are looking in the right spot at those plugs... plugs tell the tale.

Honestly the longest run I do is about 3-4 minutes. Other than that I'm usually idling around looking for brush piles. Yes, I let it idle most of the time because I'm usually circling trying to find a pile after I come off plane. This has the OMS system that mixes oil in the gas. Fuel pump is only 3-4 years old. May take it out tomorrow and see if the new plugs fixed it. I've been running sea foam in the last couple of tanks. It could be the carbon coming off and fouling the plugs.

How much Seafoam do you mix per gal of gas Jacob?

I put one bottle in a full tank. I think mine holds 17 gallons.

Well, just took it out for a test run with just putting new plugs in. Not a single hiccup. I took the wife and ran it for probably 20 minutes. Stopped started numerous times to put a load on it. Never skipped a beat. Got it up to 50.2mph with my wife and I both in there.

Ok, so here is a pic of the plugs in order from 1-4. #1 is the dry one. I took the carb apart a few minutes ago and sprayed carb cleaner through it. I don't think I have a low speed jet. Or else I don't know what it looks like. I cleaned out the high speed one behind the plug and there was a tiny long metal pipe passageway that sticks down into the side of the bowl that I sprayed out. Sprayed through every hole on the carb. All were clear and the bowl itself was spotless. No trash at all. I ran it afterwards and the plug was still dry. Should I mess with my mixture at all. The others all had a nice trace of oil.

Did you move #34? Idle circuits are under 30&31 http://www.boats.net/parts/search/BRP/EV...20HP/parts.html

Gary, you're getting to the root of my problem where I really think I need help. Do I need to take off the idle circuit cover and clean in there? I shot cleaner through the circuit from the pipe that leads into it and the little opening on the front of the carb that goes in there. I even blew with my mouth through the idle circuit. I could get air through but it was a little difficult. I figured that was because the openings were so small. I did not remove 31 or 32. Can I richen up by turning that #34 screw counterclockwise?

Most will tell you not to touch the idle air adjustment. Yes you need to clean there. Yes but move only at small increment's. Like 1/4 turn. Check one of the other carbs, count the turns or part of turn by gently turning to stop, return it to original position, then set the #1 carb same and see what that does. I had a 140hp Johnson with the plastic carbs that I had to clean out the fuel lines and fuel supply manifold 3 times before getting it right.