outboard gods , need help

[phatdaddy]

having a fuel problem, tell me what you guys think:

motor: 94 150 Merc 2.0
symptoms : bogs down on take off. intermitent might do it once out of 5 take offs

what i have done so far: changed fuel pump checked all fuel lines and tightened
checked filter

i concentrated on the fuel delivery because the ball would be empty. but the fp took care of that, now the ball remains hard. would a carb problem cause this symptom? the motor is 18 years old (1400 hrs)and i have never had the carbs off.