High rpm miss

[Ponemah Jim]

99 4 stroke Merc 40 3cyl carburated. 4000 rpm and above miss. Maybe every two seconds feels like a jerk. Not cavitating, just went thru the carbs for ethynol issues in the needle valves so I know its getting gas, Replaced fuel pump/filter/spark plugs. Low use pontoon engine. Seems like a bad wire would show up at low end acceleration? Do coils cause this? Been doing this for years intermittently.

 

[enginepower]

Check each wire and make sure it can jump a gap of at least 3/8". A coil COULD do this and sometimes an ohm check on the secondary circuit may reveal it. Since it does it more under load at high rpm, it's probably a weak coil but could be other things.