Pumps water intermittently??

[hastingsml]

My '81 Mariner 4hp 2 stroke pumps intermittently. When it quits pumping steam comes out. I shut it down and wait a few minutes then it pumps ok for a few minutes then steams again. I replaced the impeller last year and it has not be operated more than a dozen times with the new impeller. I will check the impeller but what should I do if it is ok?

 

[north40]

Re: Pumps water intermittently??

Did you replace housing or just impeller? Did it pump good when you first changed impeller? Sounds like impeller is gone again. Check that housing is not scored or pitted; if so you should buy a complete repair kit. Make sure that key is in place. Blow out water passages in case there may be something blocking flow...sounds like bad impeller though.

 

[cjcocn]

Re: Pumps water intermittently??

First off, I am in no way an outboard specialist.<br /><br />However, I just seized up my merc last month because my thermostat failed. Could this be a thermostat problem wherein it is starting to seize up? (what I mean is that the thermostat may be old and corroded and therefore sticking).<br /><br />I just thought that I would add this info as I could have saved myself a whole lotta headaches by knowing to check the thermostat and if this info will help you .... well, here it is.

 

[mikebc]

Re: Pumps water intermittently??

It's a bad impeller or a cloged tell tale path. Mine was a bad impeller, did exactly what you describe, but the impeller was 30 years old, yep, 30. Try a piece of weed whipper string right up the tell tale hole, if still no go, you gotta impeller that's bad. Just my .02.

 

[joblo33]

Re: Pumps water intermittently??

That's probably not steam, it's exhaust. The exhaust cover gaskets probably failed and as the exhaust pressure builds up it begins to enter the cooling system. It's a very common problem and the gaskets are usually about $5-10 each to replace, there are two of them. For the pisser to stop entirely there might be a combination of this problem and a clog or maybe it's just a large exhaust leak. Usually they still spray a tiny amount of water.<br />Eric