My motor is a 200 HP XP Evinrude motor, Model No. E200STLESE, S/N G02519201, received new on 10/21/89.<br /><br />Is there anyway to adjust the water control valve (P/N 394407) on this motor? The OMC Service manual, P/N 507875, page 4-28, indicates this valve should dump the water from the...