Mariner 4 O/B water "tell tale"

[lydiamight]

Mariner 4 O/B water \"tell tale\"

I have a Mariner 4 outboard engine--a twostroke dating, I would guess from around 2000/2002. It came with my boat when I purchased it so unfortunately I don't have a manual for it.
It's not been used for a couple of years,other then a couple of test runs in a wheelie bin full of fresh water.
Got the engine out tonight with the intention of using it over the weekend--question is--should the stream of water that comes from underneath the engine cowling be continuous or not. When running it up to full operating temperature the water stream seems to alternate between a stream of quite hot water (hot enouggh to wash your hands in) which then becomes a dribble and then stops all together--just a jet of steam comes out. It will then revert to a jet of hot water and so the cycle repeats itself. Should it be like this because the thermostat is cycling or is there something wrong with it?
Tried poking out the various water inlets and outlets and everything seems clear.

 

[Malcb]

Re: Mariner 4 O/B water \"tell tale\"

Should be continuous. Sounds like salt build up in the cooling syatem.

 

[alb40]

Re: Mariner 4 O/B water \"tell tale\"

My one gives a steady stream when running. Is usually cold when you put your hand under it.

I dont think the engine has a thermostat, so id suspect a new impellar should do the trick and have her pumping again, as the can go brittle if its not used and come off their metal inset.

 

[VicS]

Re: Mariner 4 O/B water \"tell tale\"

A good place to get help with outboards is the iBoats forum where you will find separate boards for each make, but be sure to quote the full model details ie make, hp year if known and the model or serial number.

Be patient with the iboats forum as they have just swapped to new software which is not behaving too well

You may be able to date your engine from the model or serial number HERE

It does sound like a malfunctionig thermostat, assuming the engine has one! As all ready mentioned the pump may need a new impeller. Partial blockage of the water circuit also sounds likely

 

[srp]

Re: Mariner 4 O/B water \"tell tale\"

I have a Yamaha 2 stroke about the same age - I think the Mariner is the same engine. Sounds as though the thermostat is crusted up with salt. You have to remove the cover on the side of the engine block to remove it. Make sure you have a new gasket available when you take it off. Take the thermostat out and throw it away. Don't replace it. While the cover is off have a prod about with a bit of bent wire to clean up the waterways as far as possible.
If you're removing the water pump be very careful - the bolts are very easy to shear off. Use heat if necessary (though if you do the impeller might suffer a bit - but you might need a new one anyway). If you shear off a bolt you're in for a couple of hours sweat and grief getting the broken bit out (voice of experience....).
Replace all the bolts with plenty of grease ready for next time.
When you've finished run the engine in fresh water again, for a good 10 minutes, to flush out all the salt crystals you dislodged earlier.
It could be that your engine doesn't have a thermostat (if its not the same as mine, or if someone has already removed it). In that case I would suspect the pump impeller. You have to try to extract all the broken bits, which can be difficult if small pieces have been pumped up the leg into the engine.
Outboards are such a pain....

 

[VicS]

Re: Mariner 4 O/B water \"tell tale\"

I would agree with all of that i think.

But be careful undoing any bolts including the thermomstat cover. Heat, release oil, gently tapping back and forth, whack 'em on the head first but definitely no brute force and ignorance.

 

[duncan]

Re: Mariner 4 O/B water \"tell tale\"

I have the same engine the same age and may have a spare manual if you need.

I would start by removeing the rubber bit on the end of the tell tale pipe and cleaning it out first - then move on from there.