I have a 2003 20hp 2 stroke OB that will not maintain Prime. Motor runs great for awhile then dies if I do not continue to squeeze primer ball. New hose and ball and vent is open on gas tank. Filters are all clean. Fuel pump?

The prime bulb line connectors may be sucking air even though it’s new.

Tom

Time to run some tests to find out.  Could be either fuel pump or new hose or fittings

Yes time to run some tests.

 

When I had issues years ago with older boats I'd hookup a 3 gallon auxiliary tank directly to the fuel supply line close to engine.

If the engine ran fine then I knew the issue was upstream.

Replace filter, hoses , tank pickup and anti- siphon valve.

If the engine was still starving for fuel I replaced the fuel pump.