1990 Mercury 75 hp 3 cylinder outboard

[Harbin]

We recently purchased an older boat with the above motor. Seemed to run fine the first couple of times we took it out. Now it will not open up. It will not go above 2000 rpm. We have replaced plugs and fuel filter. Prop looks good and seems tight with no vibration, yet the motor is running so slow/rough, the boat is vibrating. Any suggestions would be very much appreciated!

 

[Barnacle_Bill]

Strong spark at all 3 plugs? Compression check?

 

[ondarvr]

Carbs Clean?

 

[1nebel0]

Stator needs to be testor...sounds like high speed is out.......

 

[Ride.race.live]

x2 on carb cleaning if it hasnt been done in a while... have you checked to see how dirty the fuel filter is when replacing?


I got a clear see through one recently and was amazed at how much crap that is pumping through it...

a good way to know if its potentially electrical in this case the high speed portion of the stator is how well the motor runs up until that 2K rpm...



its running rough hard starting ect id be looking for into carbs and compression.. if its running mint until that 2K rpm id be for sure jumping to ohm testing the stator