Thanks Guys, Seems there is something I can do, Good, now to find it!
Injectors are new, fuel lines, filter, and fuel pump , regulator diaphram all new. PSI constant at 32 - factory spec 30psi so I will turn it down. Injector spray is a perfect cone and no drips or leaks (but will check again). It does however struggle to start on occasion when hot but full throttle gets it going quickly. I always idle to shore so no quick shut down.
Checked and no Codes. Timing dead on 10degrees while in diagnostic and it sits still. Was showing code 44 last time and I changed the knock sensor so its new. I still have a stutter/ misfire at about 4500rpm but it has always been there.
ECT new, MAP sensor new, AIC new, thermostats new. New plugs, new plug wires, new distributer cap and rotor. Also new impeller. All changed in stages over winter trying to get it running and reliable.
Also new MDC.
Will pull plugs today and check, will also check oil.
I would have thought a slightly smaller prop, with a taller pitch would help reduce fuel consumption not increase it? Will do further research on this.
Mastercraft dealer refuses to service any Mastercraft boat prior to 2004 as they did not import it so I have no help from them. There are other guys I can use but they are 4 hours drive away so hesitant to do so if I can solve myself.
Thanks so far guys