1996 Mercruiser 5.6 liter losing power

[abeletsky]

[h=3]Boat engine (Mercruiser 5.6 lt) continually accelerates & decelerates at speed until I bring the throttle down?[/h]I just put the boat back in the water after 2 years. At low speed (less than 20 MPH) the engine runs fine. When I try to accelerate, it starts to accelerate and decelerate (like someone putting their foot on the gas and removing it continuously) until I throttle back down.

Would anyone know what can cause this?

 

[Master mechanic]

Welcome aboard !

Prop spun.

Put a known good prop on your drive try it now post back.

 

[guyjg]

back in the water after 2 years...it starts to accelerate and decelerate

IF the RPM go up while the boat slows then I agree w/MM above. If the RPM increase/decrease (oscillates) then look for a fuel issue. Is the fuel 2 yrs old? Was it preserved when stowed?