Re: How can a 150 evinrude not on the VRO
Pressing in the key energizes the primer solenoid. That's essentially an electrically operated valve that allows a little extra raw fuel to flow directly into the intake manifold, bypassing the carbs. Since this helps keep your engine running it's a good indication that your engine is running lean. This will normally be a symptom of carb issues.
IF the problem were fuel pump related you'd expect to see an improvement when you pump the bulb in your fuel line. Since that doesn't help it's probably not the fuel pump.
You said you've already ordered carb kits, so very thoroughly clean the carbs and put in the new kits and see if that helps.