Losing RPMs

[tullos]

I have a 1998 Johnson 70hp outboard the motor runs fine at idle.
When I go full speed the motor loses power and RPMs. Couldthe fuel hose or bulb be sucking air?

 

[guyjg]

Use the choke; if RPM increases you have a fuel problem.

Couldthe fuel hose or bulb be sucking air?

Yes. Make sure the tank vent is open. Carbs may need cleaning esp. high speed jets.