2.5 ain't feeling well

[reflect]

I've got an early '90's 2.5 carb motor that normally runs about 6200 on my Cougar 21MTR. Here's the scenerio: All this past season it's off the trailer and you can only run it up to 5000 for the first 30 mins. Then, instantaneusly, the boat would lunge forward and pick-up that last 1200 rpm's. The temperature gauge for the left bank reads ice cold (100 degrees) then would rise to l50 (normal). I changed out the switchbox for that side -- no change. Plugs look good-they're new as well as wires and stator. I get the feeling something electrical is getting warmed up from the block than making contact. Weak coil? Last time out it started doing it in increments. It would slobber up to 4000 after 15 mins. it would lunge forward to 5000 another 15 mins. it would do the same thing then go to 6200. It's like it's dropping 2 cylinders, then 1 then OK. I ruled out the fuel system, carbs have been rebuilt, holley red at 4 1/2 lbs. Any insight would be greatly appreciated. Thanks in advance.

[johnboy 88 vegas]

Make sure you dont have a water leak hosing down a plug wire or coil before you do anything else.

[200VEGAS]

If you have an idea what cylinder it is, you could use a timing light or 2 and tape trigger shut and tie it down with something pointing forward. Run it till it messes up. You could tell if your losing it. At the least you could rule out ignition if they all check. It be cool to have 6 lights hooked up and do um all at once.

[Jay Smith]

ALSO : Check the "health" of your fuel feed line , some of these inner lines will collaps as this "corn squeezing" fuel we have to run ruin the inner part of the fuel line causing starvation of fuel flow ..

Jay