85 johnson 70hp fuel pump lines

[ambrotone]

so the vro is gone and the regular fuel pump is on. i replaced the old fuel lines and i noticed the nipples are different sized coming off the bottom of the pump. do i need to use different sized lines. the boat will run for a while then it looses power like it is starving. i can stop and rev it in neutral for a bit til it pics up, sometime even go backwards for a short distance, then it will go fast again. its is very strange.