02-20-2003, 09:07 PM
WalleyePaul,
Your motor is fine. I'll assume it's a newer (post 1980) outboard. Here is the way Mercury and most other engines operate. The stream you see coming out is called the thermal bypass line. This allows water pumped by the impeller to exit the engine without going thru the internal parts. There is a thermostat just like in your car in your outboard, it doesn't allow water to reach the internal parts of your motor until the engine warms to 130 degress (give or take a few depending on type). Once the engine warms to the temprature that the thermostat is set at, the thermostat opens. This directs the water thru the internal water jacket surrounding the motor. This hot water is then expelled out the bottom of the engine thru the center of the prop. This feature is know as thru hub water exhuast. To check if everything is working properly heres what you do. Put the hose and cups on the motor in your driveway, once you start the motor you'll see the water coming out the ports in the back. As the motor warms up the stream will get smaller and you'll see water starting to come out of the center of your prop. If there is no water coming out of the center of the prop, but, a small exhaust port above the skag facing aft, it does the same thing. It just means your engine doesn't have thru hub water exhaust. As you increase the RPMs in the engine the water should come out faster as the RPMs increase. This checks to make sure your impeller is not cavatateing (sucking air instead of water). I've made some assumptions here not knowing all the particulers but I think your motor is fine.
Your motor is fine. I'll assume it's a newer (post 1980) outboard. Here is the way Mercury and most other engines operate. The stream you see coming out is called the thermal bypass line. This allows water pumped by the impeller to exit the engine without going thru the internal parts. There is a thermostat just like in your car in your outboard, it doesn't allow water to reach the internal parts of your motor until the engine warms to 130 degress (give or take a few depending on type). Once the engine warms to the temprature that the thermostat is set at, the thermostat opens. This directs the water thru the internal water jacket surrounding the motor. This hot water is then expelled out the bottom of the engine thru the center of the prop. This feature is know as thru hub water exhuast. To check if everything is working properly heres what you do. Put the hose and cups on the motor in your driveway, once you start the motor you'll see the water coming out the ports in the back. As the motor warms up the stream will get smaller and you'll see water starting to come out of the center of your prop. If there is no water coming out of the center of the prop, but, a small exhaust port above the skag facing aft, it does the same thing. It just means your engine doesn't have thru hub water exhaust. As you increase the RPMs in the engine the water should come out faster as the RPMs increase. This checks to make sure your impeller is not cavatateing (sucking air instead of water). I've made some assumptions here not knowing all the particulers but I think your motor is fine.