The starboard engine on my Monterey 296 crusier (Merc 250 hp, 5.7) does not like to idle. It starts and runs ok and idles fine from cold or from hard running for about 20 minutes, then it slowly looses RPM and stalls. I need to pump the lever in order to restart it like it is fuel starved. I can keep it running by advaning the throttle, but it stalls if I try to shift it. At WOT it also has reduced power. The Port engine runs 4600 rpm and the starboard only runs 4200 rpm. What should I check?<br /><br />Thanks 