Older Mercury Motor Water Pumping Question

[lr1122]

I have an older (1980`s) vintage 18 hp mercury outboard that was given to me and the motor starts and runs fine. I have only run it for a minute or so in a barrell of water to verify that the water pump is working.
Where on the motor would I expect to see the water if it was pumping coming from ?

On the back of the motor there is a series of 4-5 small holes and on the back of the cowl there is a hose running from the engine block to a fitting on the cowl - should water be coming out of any of these holes ?

Prior to starting I pulled the lower unit to inspect the pump (had been sitting for many years) and it looked to be in decent condition - any clues?

Thanks

 

[Mac uk]

Re: Older Mercury Motor Water Pumping Question

Mercury 18hp ran from 1980 to 1985. should have a type B powerhead.
If the water pump is operating, a water mist will discharge from the exuast relief holes at the rear of the drive shaft housing.

 

[lr1122]

Re: Older Mercury Motor Water Pumping Question

How about water coming out of the hose connected to the engine and running to the back of the hood cowl - should water be coming out of this or just exhaust? Thanks

**Also the serial number is 9348179 can you tell me the model # and year ? no other information on the tag except made in Belgium.

 

[eclipseturbors]

Re: Older Mercury Motor Water Pumping Question

Try a deeper barrel. When I set my 18 in a shallower bucket enough to cover the pick ups and the cav plate, then it would mist and do what you are describing. When I brought it to my house to rebuild the carb in it, I set it in a deeper barrel with more water in it. It starts to pump right away. Did the same at the lake this weekend.

 

[Mi duckdown]

Re: Older Mercury Motor Water Pumping Question

If you pulled the lower end to inspect.? you should have changed the impellar. why go thru all that and not change the impellar. 25 bucks.
The pee hole tube probably has a blockage. Remove tube from block an blow it out. It doesn't take much to plug one up.
But by all means change the impellar. cheap insurance.
Personally I like muffs to check water flow. Barrels create too much aeration.