Mercury 650 thunderbolt 1975 water coming out of exhaust after impeller change.

[Cheap Cooper]

Hello! I Just replaced the impeller on our 1975 Mercury 650. There is now waster coming out of the exhaust just below the cowling on the top of the motor. There is also no water coming out of the hose where it is supposed to. I wonder if the pipe that attaches to the impeller is not sticking into the right spot and just spurting water out of the exhaust? When I start it up it takes about 20 seconds for water to start coming out of the exhaust and no water is coming out of the hose. I shut the motor down several seconds after the water started to come out of the exhaust. It is like a spray not really a trickle.

Thanks,

Cooper

 

[Chris1956]

Re: Mercury 650 thunderbolt 1975 water coming out of exhaust after impeller change.

Does water come out the prop hub? Does it exit the grating above the antiventilation plate? I will bet yes on all accounts. Stick a wire up the telltale and unclog it.

 

[ajgraz]

Re: Mercury 650 thunderbolt 1975 water coming out of exhaust after impeller change.

OK, water is supposed to come out the exhaust holes (two small squarish holes, right?) on the rear under the cowl, and it will look like a coarse-dropleted spray. Did it NOT do that before the impeller change?

If the copper pipe was not seated properly into the bottom of the exhaust plate, you would not get the spray from the back under the cowling, all the water would drop down inside the leg and come only out the thru-hub.

As to water not coming out the peehole, did it come out AT IDLE before the impeller change? Sometimes it takes quite a while at idle--especially if your motor idles well at very low idle rpm, like 650-700rpm, in which case maybe never at idle--for the head's jackets to fill enough to get water to the very top and out the peehole hose. So if using the wire to try to unclog doesn't seem to change anything, try using the warm up lever to idle up at like 1000-1200rpm briefly to see if water gets out the peehole then.

If all that doesn't work, you might have a clog inside the jacket, perhaps at the peehole hose's L-fitting, perhaps a bit of old impeller. Did your old impeller break into pieces?

EDIT: just noticed this is your first post, is this motor new to you?