Running rough

[joe65]

I have a 2010 Mercury 40 hp 4 stroke 3 cyl. The engine runs smooth in neutral and in reverse.
When I shift into foward the engine runs rough and shakes. The engine will run good after it reaches about 1100 RPM. I have replaced the plugs and fuel filter and had the injectors cleaned.

 

[QBhoy]

I have a 2010 Mercury 40 hp 4 stroke 3 cyl. The engine runs smooth in neutral and in reverse.
When I shift into foward the engine runs rough and shakes. The engine will run good after it reaches about 1100 RPM. I have replaced the plugs and fuel filter and had the injectors cleaned.

Hi. Is the prop on right ? In good condition ?

 

[joe65]

I have a new prop on it. I had the same problem with the old prop.

 

[QBhoy]

I have a new prop on it. I had the same problem with the old prop.

Did you have a small white plastic ring behind the prop in she exhaust hub area ?

 

[joe65]

no.