Wish I could post pictures... Pulled out the carter fuel pump assembly and replaced what was left of the old fuel filter. Had started to disintegrate and pieces were stuck in the pump inlet screen. Only about 50% of the screen clear for fuel to flow.
I think this might be why the motor is missing at high rpm and high loads....
Have also replaced Temp Sensor and as per seperate post, found loads of Muck stuck arround hole where the temp sensor fits. Now new temp sensor, clear to have maximum water flow should solve over heat issue with computer reducing RPM to 2000.
Yet to get it out on the water... way too cold down under, but will try next weekend.