i have a 90 hp 1988 nissan outboard that has begun to bog down after 10-12 seconds on plane. it runs great at the hole shot, but as noted above, it drops to idle speed after ten seconds or so. after the rpm returns to idle, it can usually be revved up for another few seconds. it will usually stay on plane longer if i just barely get it on plane and then pull the throttle back to 3000 rpm. any ideas?