1999 175, fuel starved?

1999 Evinrude Ficht 175. Starts and runs (low speed) okay. If throttle is advanced to about the point the boat would plane (no tach so don't know RPM) it won't go faster, surges a bit but never really gets going. If you squeeze the bulb it goes fine. Sometimes it keeps going, sometimes you have to keep squeezing. Pressure (at valve, rear of engine) 25lbs.

I tried a remote tank. I replaced fuel hoses, including bulb. All (fuel line) connections tightened. Replace fuel filters (external and internal). by-passed external fuel filter.

Based on what I have done (including connecting engine with short hose directly to small portable tank), it appears the problem is the engine, not fuel supply, but the engine goes fine if more fuel is supplied (by squeezing ball).

Ideas, suggestions?
Thank you.

Fuel lift pump needs rebuilding

Forgot to mention, I did that too (rebuilt lift pump). Might I have screwed it up and need to do again?

Is there any way to test it? How does it "pump"? Seems like more of a filter than a pump.

Purchased and installed official Evinrude (not after market, just in case) rebuild kit for lift pump. Took for a test ride yesterday, no change, still no top end without pumping the bulb.

Any other ideas?

The lift pump pulls fuel from boat fuel tank, then thru canister filter to VS with electric pump. Since its running the VS and electric are ruled out as its a supply issue. If it runs fine except for WOT its the lift pump,air leak in pump or crankcase pressure is low to drive pump.

Thank you for your response(s). To be clear, it is not just WOT, the problem starts at about the RPM that would get the boat on a plan. Idles okay, can give it some gas (up to 8-10kts?) then it doesn't want to go faster (surges a little but won't get or stay on plane).
Am fairly certain is not supply issue (used remote tank and bypassed external filter).
Don't think there is an air leak (have tightened and retightened all hose clamps, screws, etc., pump rebuilt, scrapped off old gaskets, all new installed, appear properly seated...)
Per your list above that would leave low crankcase pressure. Any suggestions what to do about that?

Do you have spark on 6 leads or just 3 ??

I haven't checked spark. I just assumed all the cylinders were firing because the motor has plenty of power, if you squeeze the ball. To me that makes it a fuel issue. I could check to be certain but I can't imagine the boat would go as well as it does (about as well as it ever did if the ball is squeezed) on three cylinders.

If you have verified that all fuel connections are good, lift pump assembled correctly, fuel cannister filter not leaking and still have this problem, the lift pump is not pulsing properly to supply the VST. This is a mechanical issue internally in engine. Could have worn /broken piston skirt, seal ring bad (never seen one on a 60°)