3.0 mercruiser won't throttle up past 2000 rpm

by Brandon
(Georgia)

I have a 1987 ebbtide with a 3.0 mercruiser
I have replaced valves rocker arms cam shaft rebuilt carb plugs wires points condenser cap rotor button
New timing gears new oil / filter
Runs good at idle but when throttling up past 2000 rpm it won't get on plane even when pushing lever all the way down will not go past 2000
It would plane out okay but wouldn't open up all the way only saw 24 mph out of it has strong compression new head gasket new manifold gasket
The boat sat for awhile guy said he ran it last yearbut I think differently
I'm at my wits end with this thing I'm
Changing the fuel filter in pump tomorrow had to order it from dealer .
I don't understand it is it not getting enough gas or is the cable not moving it all the way open ?
Is there a filter in the tank ??
Would a electric pump help any? Could it be the plugs ?
Has anyone had this issue ? Please help