Sorry for the stupid question, but how do i tell if my mercruiser 120 is pumping water. I just bought it and am ready for the water, but ive always had outboards, and i know where they spit water out. Where do the I/O's come out?
depending on what drive you have, may come from the inside of the prop hub, out the exhaust tube or from the through the hulls if you have captains call exhaust. start it up on the trailer with muffs on and seee where it comes out. If you have a Merc with a bellows it will come out through the prop with the exhaust. If it has a water tube it will come out of the exhaust tube with the exhaust. If it's not pumping water you will know when it gets hot . Exhaust manifolds and risers should not get hot enough to cook on.
I started it up for 30 seconds, with bellows on and water came out of the prop. The reason Im asking is the day after i did this i changed a hose and it was bone dry. Is this the doings of the thermostat? why would water come out of the prop but not circulate through the engine.
what kind of engine/drive do you have? Not a good idea to start up with no water , the water pump impellar does not like to run dry. It will trash it in seconds.
Hook it up to flushetts(muffs).Then inside the boat follow the hose from the back of the transom to the thermo housing.Disconect this hose and start motor.It should push a lot of water.The faster you rev it the more water(unless low pressure in hose) it should pump.
But if your worried change the impeller.Jerry
