Can anyone help? I have a 1981 75hp Evinrude all three carb's just rebuilt, linkage and cables are correct, timing and carb's are in sync all according to the manual. Compression test shows number 1 cylinder 119, number two cylinder 120, number 3 cylinder 121. Compression check ran twice using two different gauges, got the same results both times. If I set the idle rpm at 750 per the manual, in gear unrestricted, in the water (at the lake not on ear muffs) the engine will die. I have to set the idle rpm at 950-1000 in gear, unrestricted, in the water to prevent the engine from dying which moves the boat to fast at idle speed. WOT timing is set at 19 degrees BTC at 5000 rpm. WOT runs great no bogging down or hesitation when pushing the throttle down. Saying all of that to get to this point; today as an ignition test, with the ear muffs on, I set the idle to 1500 rpm, pulled the spark plug wire from number 1 cylinder, the rpm increased 300 rpm, I turned the engine off, returned the plug wire back to number 1 cylinder, started the engine and pulled number 2 plug wire, there was little or no change in rpm, turned the engine off, returned the plug wire back to number 2 cylinder, started the engine and pulled number 3 plug wire, the engine died. I repeated this procedure three times and on each occasion the results were the same. Does anyone have any thoughts as to what is going on? Should the change in rpm be the same across all cylinders?
