5 hp 1995 mariner, New impeller not circulating water.......

[John227]

I have a 5 hp mariner outboard engine, 1995. It was drained and stored for 15 years in the basement. I recently brought it out and was able to get it started fairly easy by soaking the carb for about 24 hours with some kind of lubricant the local auto parts guy recommended. New plugs and she cranked right up.

My Question: I didn't notice that the engine wasn't circulating water and ran it for quite a while before noticing how hot the engine was getting. I discovered that the impeller was shot and replaced it. The engine/tell tale still wont "****" (sorry, not sure about the terminology) I can put a hose up to the intake and get water to come out of the tell tale tube right below the engine so I don't think it is blocked.

Any advice? I hope I have provided enough information.

The impeller is brand new and the water pump housing itself looks just fine. I am at a total dead end

 

[Texasmark]

Re: 5 hp 1995 mariner, New impeller not circulating water.......

Around here mud dobbers (insects in the hornet/yellow jacket family) love to make cocoons out of mud and outboard engines are perfect. Plugging water exhaust passages are not exempt. Good part is that once you put water to the engine, in a short time they will dissolve and most of the mud will wash out on it's own; larve may not.

The water pump sucks up water from the lower unit from visible holes in the housing forward of the prop . Water is discharged from the top of the impeller housing (water pump) via a port on top of it where a semirigid (copper) tube conducts water from the pump to the bottom of the engine block. If that tube is not properly inserted at both ends, the block can't get any water.

So, when you reinstalled the LU after the impeller change, did you ensure that the tube was properly positioned?

On the engine getting hot accident, (larger) engines that have over temp sensors, which operate at around 190F. If they have thermostats, they open around 140F. A US domestic hot water heater set to the Normal position produces water at 140F for a reference and water boils at 212F at sea level for another. So, unless you were smoking paint, i wouldn't worry too much about hurting anything initially.

Mark

 

[CharlieB]

Re: 5 hp 1995 mariner, New impeller not circulating water.......

Are you SURE that the drive key for the impeller is in place?

If the key fell down out of place as you slide the impeller down, it will not be turned by the vertical shaft and will not pump any water, yet when you push water thru with the hose all will seem well.

Re-inspect the water pump, make sure that the impeller key is in place locking the impeller to the shaft.

 

[John227]

Re: 5 hp 1995 mariner, New impeller not circulating water.......

Thanks so much for responding to my problem.

I will definitely double check to ensure the key is properly in place but I am fairly confident I reinstalled everything correctly. I will also recheck the copper tube.

Another thought. Is possible that even though I can push water through the intake with a hose and get a stream from the tell tale that pieces of the old impeller may still be blocking the system?

When I pulled the old one out it was in many pieces. Think pieces may still be clogging somewhere despite the garden hose?

 

[John227]

Re: 5 hp 1995 mariner, New impeller not circulating water.......

Great news about the overheating. No paint melting but I did lose power. I have been worried the circulation problem might be attributable to a larger (expensive) problem as a result of over heating

 

[Texasmark]

Re: 5 hp 1995 mariner, New impeller not circulating water.......

You are on top of your problem sir. Pieces of the impeller that can make it up through the tube to the power head "can" clog water passages. Course if they are so large that they cannon make their way up the tube than you will have them at the pump and they can be removed.

Loosing power can be from mechanical resistance caused by the expansion of the piston/rings caused by the heat. Don't commit harey carey until all is lost. A lot of problems/potential problems are in our minds....BTDT.

Mark