225 EFI wont idle and stalls

[Robert Hanft]

1997 225 EFI 650 hours When I throttled back the Starboard motor RPM’S dropped to 300 and the engine stalled. I could not get the engine restarted/running unless I ran the RPM up to 1500 as soon as I brought the throttle back it would stall. Primer ball hard, fuel at normal level in engine mounted filter housing, (new filter)3 new l/p fuel pumps, vst filter cleaned and pressure 35 psi, on vacation for a week tried yesterday and the engine started but RPM’S dropped to 300 and stalled. When I pressed the Schrader valve stem allowing some gas out it the RPM’S seemed to increase. Any ideas????

Thanks
Bob H