water around spark plug 70 hp mariner

[dwe9434]

I just bought a 1981, 70 hp mariner. After starting it with muffs I noticed that there was no water coming out from the pee hole, I shut it off right away but noticed some water pooled up around the top spark plug, and while it was running it had a little bit of water coming out with the exhaust. Does this sound like a craked block? If so, how did it have enough water pressure to buck the compression if the water pump is bad?

 

[schematic]

Re: water around spark plug 70 hp mariner

its likely that your telltail is plugged and your water jacket cover gasket needs replacement. Wouldn't hurt to inspect water pump as well.

 

[dwe9434]

Re: water around spark plug 70 hp mariner

I know that the water pump is bad because I found pieces of it when I took the water jacket cover off. It spits a water mist out the exhaust when running, is this normal? When I replace the water pump should I get the whole kit or just replace the impeller?

 

[Texasmark]

Re: water around spark plug 70 hp mariner

You are going to have water discharge from the lower unit. On that engine it will run out the bottom of the exhaust in the prop hub. Sometimes you will get some water from the pressure relief vent holes on the top rear of the mid section. How much and at what rpm depends upon how the passages are designed for your engine.

Pieces of the water pump impeller is not good. The question is where did they go? Not familiar with an '81 70 mariner. Not familiar with the plumbing for the tell tale. Different engines have it in different places. Some it comes directly from the exhaust manifold water jacket and you should have a stream of water any time the engine is running. Others plumb off the stat and you have to have the stat opening to get any water.

Most folks remove the lower unit and the stat and popoff if it has one and flush out the engine with the garden hose best they can. Running a wire through the pee tube and fitting will usually help if water alone can't clean it out.

My manual says if the gouges in the bottom plate of the water pump, where the impeller rides, are more than .030, get a kit. Otherwise just an impeller.

Mark

 

[dwe9434]

Re: water around spark plug 70 hp mariner

The exhaust I am talking about is right below the bottom of the hood/cover. Thanks for all your help!

 

[schematic]

Re: water around spark plug 70 hp mariner

IMHO I would replace the whole pump. It comes with a lower body which will freshen the lower driveshaft seal. Also, if paddles are missing off of the impeller, its likely the engine was run "out of water" and damaged the pump housing plastics. As Mark suggested, inspect the poppet and thermostat for fragments and flush flush flush

 

[Texasmark]

Re: water around spark plug 70 hp mariner

IMHO I would replace the whole pump. It comes with a lower body which will freshen the lower driveshaft seal. Also, if paddles are missing off of the impeller, its likely the engine was run "out of water" and damaged the pump housing plastics. As Mark suggested, inspect the poppet and thermostat for fragments and flush flush flush

Yeah, on that engine, I would go for the whole pump too even though it's over $50. May save you more expensive problems later.

 

[dwe9434]

Re: water around spark plug 70 hp mariner

Thanks guys for all your help.