95 johnson fast strike throttle blades not opening

[lugnut172865]

I have a 95 Javelin 379T,johnson fast strike 150, My throttle cam broke on the water and while fixing it,I was checking my throttle blades at wide open,and they are only open 1/4 Boat runs good about 45 with 2 people But after watching a u-tube video on hole shots,it was apparent mine was lacking It takes it time coming up on plane I am new to bass boats so im still learning about trimming,but I cant imagine it running that good with only 1/4 throttle open Is there a adjustment or how can it be that far off It would be a rocket with the blades fully open HELP!