90 HP EFI trouble

[wrecmaster]

Have 90 HP EFI 4 store that is give me trouble since owning it. Well maintained every year (oil, filter, gas filters, water separator filter) all changed religiously. Runs great from 0 to 4000rpm not a hiccup but push it up over 4000 rpm and motor starts wanting to lose power but not completely die. Bring throttle back under 4000 rpm fine. push back up same results.
Any ideas Thanks

[boats.net]

Sounds like starving for fuel, may have a fuel restriction in supply hose or pickup in gas tank or a bad anti-siphon valve at tank.

[wrecmaster]

90 HP problem

We disconnected main tank & hose to motor. hooked up separate 6 gallon tank still same problem. HELP

[boats.net]

Check fuel pressure at full throttle to see if loosing pressure.

[wrecmaster]

pressure is good all the time until it decides to act up. I have been told could be Fuel Lift Pump acting up. Anyone cross that rod before?