i have a 85 85 hp force ive had it a few yrs with limited trouble but i had to replace the impeller this yr and now the boat doesnt run right. itll star fairly easily and run as long as i have it throttled up in neutral. it will run when i throttle down but wont run for long before it will sputter and shut off. iput new plugs in it and cleaned the carbs. i think its a coil gone bad but the plugs all look the same. the only time u notice the trouble is on the water. itll run at no wake speed fine but when u up the throttle to get the boat to planing speed it wont open up. it goes just fast enough to cause a wake and thats it. i thought the gas was too rich so i leaned it up a little to no avail. i do mix it 50:1. any help would be greatly appreciated