2008 mercury 4 stroke outboard running rough above 2200 rpm...

[songbirdskipper]

new member here. i have a 2008 90 hp mercury efi 4 stroke outboard which was running like a top a week ago. today it started quickly and idled well then the rpm would not exceed 2200 rpm (sounded like a sensor was limiting rpm) and the alarm sounded. engine was running very rough when asking for power above 2200 rpm. i changed the plugs and blew out the fuel filters. i use only ethanol-free gas. no help. engine runs perfectly below 2200 rpm. are there sensors i can change? what kind, how many and where located please? trying to save a vacation. thanks in advance....

 

[mechanicman]

When the alarm went off . Was it a steady tone?

 

[songbirdskipper]

When the alarm went off . Was it a steady tone?

no, the tone was intermittant. thanks for your reply. it stops completely when the throttle is retarded to idle.

 

[mechanicman]

You .may have a sensor out of whack or a loose connection at a sensor

 

[songbirdskipper]

You .may have a sensor out of whack or a loose connection at a sensor

i checked everywhere i could see for loose wires, etc, but no luck. took it in today. i'll post on here what the problem was in case it will help someone else... thanks for the replies...