2000 baja 232 502 mag mpi.

When I set initial timing it idles around 1500.
When I throttle up the boat runs like it’s running out of gas. It will not get passed 5 mph. It sputters really bad. I know it’s not fuel pump I have brand new aeromotive fuel pump and I get 45 psi from regulator. It almost seems like it’s in like a safe mode. The engine is new and the injectors where cleaned and inspected.

I think yours is a MEFI-3 right

Assume you placed in base timing mode to set timing. It should idle at 600 rpm when not in base timing mode
Is there a paper clip in the DLC connector keeping it in base mode?

I am plugging timing tool it idles down I set initial timing to 10 degrees unplug timing tool and it is idling at 1500. I should say I set the timing in the water as well.

On the hard or in the water shouldn't matter with the MEFI

When placed in base timing mode some things are disabled. I'm wondering if there is a vacuum leak. Do see the need to scan the motor and see what the sensors are doing

I would need someone to do that for me. I was hoping to avoid that. I not sure what codes there are on ecm. I put a vacuum on it and no leaks.

Fuel pressure is good, but we don't know if the timing is advancing, what the MAP is doing

Have you triple checked the firing order?
Are all plugs firing?

You put a vacuum on it? Or did you check manifold vacuum with a gauge? (Engine running of coarse) So what was the number it reached? Was the needle steady or fluctuating?

Yes manifold vacuum I believe it was between 10-15 stayed steady. Firing order was checked. I am having a marine tech run a scan and see what is what.

check the fuel pressure under load at rpm... the vst tank has a micron filter that can get plugged up resuting in the symptoms you described,,,

I don’t have the vst. I have aeromotive 750 with 1000 micron before rails and aeromotive regulator