Mecruiser 4.3 MPI Carbon Issue

[JJ Fish Fear]

Hi Guys

We recently obtained a Trophy pro 2052, 2005 model with a Mercruiser MPI 4.3 we replaced the water pump on the motor and cleaned the feul system with quick clean from Mercury, on test she was going well and went up to 5000Rpm all pressures was good and temp consistent.On return back to port you could see carbon in the water ,black smoke and she was not clean revving anymore can anyone please give us some direction on the possible cause.

 

[AllDodge]

Seeing it on the water means one or more of the cylinders are running rich. Pull the plugs and see which ones have carbon build up. Once those are identified then it can be determined which injectors are at fault

And fuel pressure be 43 psi with vacuum line removed off regulator and no lower than 38 psi at idle

 

[Bt Doctur]

Once identified they can be sent out for cleaning , and if you have "cool fuel III" remove the water drain occasionally to prevent it from clogging and causing run ability issues with the MPI fuel injection

 

[jimn]

Hi Guys

We recently obtained a Trophy pro 2052, 2005 model with a Mercruiser MPI 4.3 we replaced the water pump on the motor and cleaned the feul system with quick clean from Mercury, on test she was going well and went up to 5000Rpm all pressures was good and temp consistent.On return back to port you could see carbon in the water ,black smoke and she was not clean revving anymore can anyone please give us some direction on the possible cause.

Did you notice a specific odor from the smoke? Did it smell like burning rubber? That likely means the impeller is toast and the bellows has been destroyed.