110 9.8 hp Quit Pumping Water

[berninga87]

Mid 70's Mercury 110 9.8. Water pump professionally replaced last summer. Been run 5 or 6 times since then.

Took it out today and after running about 5 minutes noticed it's not pumping water. It was pumping when I left the dock. Put in a barrel at home with clean water and nothing. Little bit of blue smoke and possibly steam but no water.

I read about an exhaust gasket that fails on these but do they just go that fast? Not sure what steps to take next.

Thanks, Adam

 

[Scott Danforth]

You pull the lower and inspect the raw water pump, then you start diagnosing from there

 

[berninga87]

I'll start with that tomorrow. Thanks.

 

[clueless75]

A lot of the time these motors just get a little bit of stuff stuck in the pee tube, which results in no water coming out. Next time you run it, just stick some wire up the tube and it should work. Always happens with the smaller older mercs

 

[berninga87]

I did take the tube off from the top of the powerhead and that was dry and clear. Are you saying to put the wire up the inlet side in case something is stuck there?

 

[clueless75]

Right where the water is supposed to come out (do this when running the motor), stick some wire that will fit up the tube as far as you can, then take it out while the motor is still running. If it's sort of clogged with dirt/sand or whatever, it should dislodge it and pee again. I do this multiple times when running my 7.5 merc

 

[Scott Danforth]

After 5 years the impeller took a set. Since it has a 5 year life expectancy anyway CHANGE THE IMPELLER

 

[berninga87]

Took the lower unit off, inspected the pump and impeller. All looks fine, impeller still looks brand new(less than 1 year old), and lines are clear from top to bottom in lower unit. I did try blowing air from the "pee hole" on the powerhead and I was unable to get any air through it.

I was thinking that the line from the top of the powerhead to below where it connects to the lower unit should be unobstructed. Is this correct? If so, I must have an obstruction somewhere in that circuit. Can I blow compressed air through the pee hole to clear it out, or is there a different method?

 

[clueless75]

I have a 1969 merc 7.5 and if they used the same design (I'm not sure if they did), there was a little rubber circle that was right where the water uptake tube connected to the powerhead, which was slightly melted and obstructed some water flow. Not sure if your motor has the same thing? Perhaps look into it?