I have a 1986 90hp merc.The other day the motor was running great and suddenly started to bog. The plugs have been changed. There's spark at all plugs. The compression is around 90psi. I rebuilt the carbs, changed the gas line. The filter is clean. The motor starts first try, and idles smoothly. At half throttle it has a bad hesitation, and at full throttle it has a miss but will only run about 4000rpm. I am out of ideas. Have had the motor for over 20yrs, other than carb problems no real issues. Any suggestions???
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