225 Promax Efi Won't accelerate

[paramount21]

Replaced powerhead...135 compression...Output tests check out fine...Engine ran perfect for first 5 hours but all of a sudden wont rev up past 15-1800 rpm in gear in the water...checked timing, made sure it was advancing...bogs and sounds just like opening the throttle body on an opti without moving the tps...Fuel pressure spec is about 34psi if i'm not mistaken..checked the fuel pressure and its about 30-31..wasnt sure if that would make that much of a difference...Unplugged bias wire and didnt notice any difference...installed 2 new switch boxes, got the same thing...

Really not sure where to go now...What would u guys suggest?

Thanks in advance

[pyro]

Try another pressure gauge, the pressure should be 39 psi. If it's really in the low 30's, it's not going to run right without a new regulator.

[luckycraft]

Check your fuel line and everywhere there are fittings for cracks and potential places for it to suck air. My brother had the same thing happen to him on a 175 yamaha hpdi. Dealer replaced the fuel pump no change. It had a primer bulb attached to the line with zip ties. We replaced zip ties with hose clamps and fixed the problem. It was pulling air around the primer bulb fittings.

[trashy]

If you check all of the fuel stuff and still have an issue, I would suspect the high side of the stator. I do agree though that the fuel pressure seems kind of low (assuming your gauge is correct).