Just bought a small jetboat and took the family out. Boat ran fine, but is too small for us. Decided to sell it. After lauching to give a test ride to a prospective seller, I let back of the boat ground (engine off) and climbed in. I thought we were floating (dock is completely out of the water, so no deep-water tie up was available while parking vehicle/trailer) and started the boat to take off at mid-throttle. I soon discovered that we were still aground (broken limestone rock/gravel bottom with gooey algae) at the back of the boat. I cut the motor and pushed us off completely and began again. After we had low-speed cleared the now wake zone, I throttled hard. The boat revved, but since we were near weight capacity, we didn't go fast. Then the engine lost some rpm's followed by the overheat(?) alarm. Once the boat was back on the trailer, I looked underneath to see if there was any debris clogging the grate (there wasn't) and then looked around the engine compartment to see if anything had come loose (nothing apparent). Upon turning the key to "on" (but not "start") for the next 10 minutes, the alarm would come on. After a little while, with the alarm off, I started the boat on the trailer, but in enough water that it was floating. It started up fine. I ran it up to as high throttle as the controls will allow in neutral. After about 3 minutes the overheat(?) alarm came on again, so I shut it down and pulled it out of the water. I've only dealt with very low hp motors before (with water tell-tales). This motor has no obvious way of checking adequate water flow - nor do I want to tear very far into it as I'm trying to sell it and get the larger boat (hopefully conventional outboard-powered). Can somebody direct me to where each item of relatively easy access I should check in the correct order? Is there a cooling water impeller like on outboards that could have gotten damaged or does the motor get cooled by the "drive impeller"? If so, is it easily changed out?
