1989 evinrude losing power

[Brianroberts83]

I've got a 89 25hp evinrude tiller handle model e25rcur. It starts fine idle great but when it's on the river when I go to give it the throttle it loses power. All I can get is a decent idle speed. I've changed the plugs carb has been cleaned new fuel tank and fittings. Best I can tell it's not getting enough fuel. The bubble primes good when the motor isn't running but I noticed when I give it the throttle the bubble is losing prime. And if I'm about half throttle I can pump the choke and it starts getting power back. Any ideas of what my problem could be or where else I can look for a problem?