Water pump not pumping

[DadaRabbit]

2001, 150 merc, carb.<br />Replaced impeller following the repair manual. Went to test it using a hose and ears while running motor. No water coming from the upper water discharge hole. I connected the hose to the upper flush connection (no motor running)and water did come from the discharge hole. Is it possible that the plastic sleeve became dislodged from the top of the plastic pump housing? Manual didn't say to seal the sleeve to the pump housing. Should this be done? Or could there be another problem?

 

[Clams Canino]

Re: Water pump not pumping

You sure the little key was in the impeller? Did you have the vanes trailing direction of rotation?<br /><br />Since the flush attachment works - it sounds like the pump itself is at issue.<br /><br />-W

 

[DadaRabbit]

Re: Water pump not pumping

Key is in and rotating in the proper direction.<br />Any thoughts on the plastic sleeve?

 

[DHPMARINE]

Re: Water pump not pumping

DadaRabbit,On older engines the plastic tube was just a guide for the water tube.Your engine needs it to connect the water pump housing to the tube in the exhaust housing.It needs no sealant,but if it falls off you have no connection.<br /> I do know that running on a flushette,it takes some time for the block to fill with water,then warm up enough for the thermostats to open,and then the tell-tale works.<br />Back the trailer in the water,run the engine.If you don't have a tell-tale in 2 - 3 minutes,I'd go looking for a problem.<br />DHP

 

[DadaRabbit]

Re: Water pump not pumping

I didn't allow it to run but 30 seconds +/- not knowing if I was causing any damage to the powerhead. Though I would see water right away. Will try again. How much run time do I have until damage will occur?

 

[andrewkafp]

Re: Water pump not pumping

Damage occurs from overheating, and if you are starting from cold, I would say it would probably run for 10-15 minutes at idle before any damage is caused. But having said that, You would likely have steam and very rough operation along with smoke from oil hitting the overhot pistons before then.<br />But you shouldn't need to run it for more than 3 minutes, for the Tstats to open and water to flow.<br />Small motors tend to fill up and start peeing quite quickly, but the bigger ones hold more water and generally take longer.

 

[KCLOST]

Re: Water pump not pumping

Those stats may not open at all at idle speed running with cold water coming from your garden hose. I was running mine yesterday in the driveway testing a new pressure guage and the engine temp never got hot enough to open the stats. However I always see a little water coming out of the pee hole even with the stats shut (just small spurts). But my motor is much older than yours, you probably should see a water streem at all times with yours.. Call mercury and ask if you should have a full water stream at idle with the stats shut...<br />Or someone should know this and answer it for you on this board.

 

[quantumleap]

Re: Water pump not pumping

My 1997 125 has water coming out immediately after start up when cold on the garden hose.

 

[DadaRabbit]

Re: Water pump not pumping

After 3 minutes running the t-stats opened, runs great. Better safe than sorry. Thanks for the info.

 

[andrewkafp]

Re: Water pump not pumping

Gotta keep an eye on them... Little problems can turn into big expenses...

 

[gss036]

Re: Water pump not pumping

I think it depends on the models. My 200 takes a little while to open the thermostats, others will start peeing like a race horse as soon as they are started. I kinda think those engines do not have thermostats or else a different type of bypass. Saturday morning at the docks, it was about 28-30 degrees, one boat started a Merc 175 and it was peeing right away, the one in front of it was a 200 Mariner (the gray Merc) and it did just as mine, spit and sputtered after about 2-3 minutes and then mostly sputter while it left the dock.