Hi, I have a 20 year old Yamaha 4 HP motor which has been superb and reliable, although it is not heavily used. Unfortunately today it seamed to overheat, stopped and would not allow me to pull the starter cord and so I assume it was temporarily seized. ( Also I could not change the position of the "gear" selector and it was physically too hot to touch) After 5 or 10 minutes, with the prop in the water, it started again only to last for 5 minutes and the same thing occurred. I have tested it in a tub of water and it seams to be pushing out water from the appropriate place suggesting that the cooling water is being pumped through the system as it should be. Does anyone have any ideas or has anyone experienced something similar ?