While cruising the other day at 4000RPM, port motor overheat light came on. I slowed motor, turned it off, looked for obstructions, etc. Finding nothing, I cranked her back up, good water stream/pressure and no overheat light. slowly took back off and didn't have another problem. Once back in the yard, I took the cover off and discovered that the bottom plug on the starboard side was really loose and oil had sprayed everywhere. All other plugs were tight and clean. Guess I didn't torque that one plug correctly at the beginning of the year. However, can a loose plug cause an overheat condition? I hooked the motor to my palm pilot and software stated that max engine temp was 190 and max emm temp was 159. Are those temperatures in the overheat range? Thanks for the help. Just wondering if I need to check other things?? Jason