91 200 hp v6 stalls on load after 1400 rpm?

91 200 hp v6 stalls on load after 1400 rpm? It starts fine but when I put it in gear and try to go faster than 12-1400 rpm it stalls out. I changed all my plugs one plug out of the six seem to be like new/ unused? I am getting spark from that coil pack. I do not know if the problems are related... Any one have any ideas??

[boats.net]

Most of the time it's a fuel problem, fuel restriction, fuel pump or carbs need to be removed and cleaned.

Thanks...... I will check fuel lines and pump in the morning.