1979 Stinger 75hp Power Pack??

[Panthers06232]

I bought this bass boat with a 79 stinger 75hp on it. Motor starts right up but has a miss at idle and bogs/surges under acceleration. The longer you run the boat on the water the worse it seems to get. What i have done so far is new fuel pump and all new fuel lines rebuilt all three carbs letting each sit in carb clean over night. The motor still does the same thing misses at idle pops every once in a while not a backfire though. I checked all three plug wires for spark with a spark tester and they all seem to be sparking. With the motor idling on muffs pull the top wire off I got a little shock and motor stalled. Second plug wire pulled off got a little better shock and motor stalled third wire no shock I can hear electricity passing through but motor bogged down a little but did not stall and that bottom plug is wet. The power pack looks old and original and the two bottom coils look original as well could this be a power pack coil problem. This is a longshaft stinger engine which to my understanding is no different than a 75hp Johnson fishing boat motor. I did also do a compression check and im running right about 125 on all three.

 

[racerone]

Sounds like there is an issue with # 3 cylinder since motor did not stall.-----Do a spark / ignition output test.----Does spark jump a gap of 7/16" on all leads , yes or no ?----Important to answer that.-----Are you aware of issues on these motors with exhaust cover gasket leaks ?---Water could spray into a cylinder ?----Check the 20 or so bolts on the exhaust cover , are they tight ?

 

[Panthers06232]

I thought yesterday when it popped I saw some smoke blow out of the side of the exhaust cover but i couldn't confirm it

 

[Panthers06232]

looking at a parts break down there is 3 gaskets behind that exhaust cover do i need to replace all 3

 

[racerone]

Well-----Motor is 40 years old !----If gaskets are original they need renewal.------I am not saying those gaskets are your problem.----I can not see , hear or feel your motor.----Repair and trouble shooting are up to you.