Re: Boat still Overheats!!!!! GGRRRRr
Hi all, I have some experience with overheating<br />my 3.0 cobra running on muffs in the driveway, and I can tell you how this was solved.<br />Assuming that you have a Cobra drive,<br />the water pump is located behind the long v-shaped cover on the back edge of the outdrive.<br />Remove the cover and the bolts holding the pump housing on, and you will see the impeller, which, if it is the correct one, should be wide enough to "fill" the housing from front to back.<br />If it doesn't contact the surfaces on either end, it cant pump water.<br /><br />Next, with the pump cover still off, check for water supply to the pump, by turning on the garden hose with muffs installed. Water should flow from the drive where the pump bolts up. If not, then you either have an obstruction, or the muffs dont seal well enough to lift the column of water to the pump. (I had this problem)<br />This is not a factor with the boat in the lake, because the water pump will be below the surface of the water with the drive down. The pump cannot prime itself.<br /><br />Next, is the priming part. The plastic? impeller housing has a small hole drilled in it to allow air to escape when the drive is submerged, or the muffs on. check this for obstruction. (I had this problem too). Because of this hole, a small stream of water will flow from under the V-shaped cover if the pump has primed. Running with the cover off, it will literally shoot a jet like a dentist's water spray straigt back. When running in the driveway, I always turn on the hose and wait for this "leak" to start before starting the engine.<br /><br />If the pump looks good, and the hole is open,<br />reassemble the pump and turn on the hose.<br />Disconnect the hose at the engine which goes down to the pump, and start the engine. Water should spray out of the hose forcfully. At least like the garden hose stream.<br /><br />If all is well, you'll need to try the same test in the lake. Submerge drive, point hose overboard and start engine. You should have a strong stream coming out.<br /><br />Now you have enough incoming lake water-the coolant. It has to circulate through the block-<br />Is the engine's water pump belt tight? In rare circumstances in my years as a mechanic, I have also seen the engine water pump impellars rust away or fall off the shaft, but you have to pull the pump to check that.<br /><br />It is easier to pull out the thermostat and run the engine to see if the problem is solved. For the price of a thermostat, you could just replace it and try again. I have seen plenty of stuck thermostats.<br />If water is coming in to the block, and the thermostat is removed, water should be coming out of the block, unless there is an obstruction.<br /><br />With a good thermostat in place, the water should exit the block when the rated temperature has been reached.<br />I hope that I have been of some help to you. Good luck!
