5 hp Mariner Overheats at Idle/Low RPM

[boaternewbie]

Hello-
I recently purchased a little 1987 12 ft aluminum boat with a 5 hp Mariner 2 stroke motor. I have taken it out twice in the 4 days I have owned it and have a couple questions about it as I am an idiot to this stuff. All advice and thoughts are much appreciated.

I starts great. One pull. And seems to idle and run just fine, however I have to high rev the engine for several minutes to get water to come out the tell tale. I then have to continue to hold open half throttle to keep the water coming. When I let off the gas water stops "peeing" out the tell tale and it turns to steam or nothing. Once it stops I have to put it in neutral and high rev the engine again to get it to start peeing out again as giving it more throttle in gear doesn' do the trick.

Like I said I am an idiot and only know the word tell tale becuase I read it on some posts.

I appreciate anyone who can help me.

Thanks

 

[emckelvy]

Re: 5 hp Mariner Overheats at Idle/Low RPM

Sounds like the impeller has lived a good life and is ready for its voyage to the Great Beyond! The fact that it won't pump a good stream at lower speeds indicates a drastic loss in pumping efficiency (i.e., it's shot!).

Seriously, pull that baby down and replace the imeller. If it's been more than a couple of years, or you don't know when it was last replaced, it's time.

You can look up parts at various places including the iBoats store, if you can't find what you need try here:

http://www.mercruiserparts.com/SelectModelType3.asp?class_id=2

HTH.......ed

 

[boaternewbie]

Re: 5 hp Mariner Overheats at Idle/Low RPM

Thanks for the reply Ed. Understand I am like a kindergardner to this. Could I trouble you to tell me where or how I might learn to replace the impeller? Also, do you know a rough price range and amount of time it takes. Sorry for the hassle, thanks for the response.

 

[emckelvy]

Re: 5 hp Mariner Overheats at Idle/Low RPM

Check out this past post for some good generic info on impeller replacment.

http://forums.iboats.com/showthread.php?t=272572&highlight=impeller+replacement

Check out the link within the above thread and there's a real good rundown of how to replace an impeller on a larger motor. The general stuff still applies although it'll be a tad simpler on your little 5HP.

Use this forum's search feature and you'll find lots more.


Note impellers are generally not that expensive, can't give you specifics without a serial #. I'd recommend looking up your motor at the link I previously posted and you'll not only get good parts info but also illustrations showing how your motor's lower unit hooks up and whether or not you'll have to deal with a shift shaft.

HTH...........ed