Running on the hose

[buckeye_paul]

I know I'm going to get some useless information for putting this out there but here it goes. Has anyone ever asked a Mercury technician if it is acceptable to run on the hose? I don't believe it is.

Here's why.

The first time I ever ran this motor on the hose, it ran about 4-5 minutes then I got the overheat alarm. From then on and until today, every time I've ran on the hose, I ran it for less than a minute just to check that it would start okay before heading off to the ramp. Today while working on a project I let it run for about 4-5 minutes and got the overheat alarm again. I have never had an overheat while out having fun and the tell tale has water running from it. While on the hose there is never water coming from the tell tale.

Here's my thinking. This is an open loop system and needs pressure to operate properly. Water can't fill the loop due to gravity. The water is following the path of least resistance and is pretty much running out the bottom without filling all of the water passages around the cylinders. While the boat is in the water, the impeller acts as the water pump. This pump fills and pressurizes the system, thus the water from the tell tale.

I'm betting a Mercury technician that works on Sport Jets, has some kind of rig that goes under the boat and allows the water to be pumped up into the motor. I have a smaller boat with an outboard motor and I can run it on the hose indefinitely. Anyway, tell me what you think.

 

[Racereddie]

I know I'm going to get some useless information for putting this out there but here it goes. Has anyone ever asked a Mercury technician if it is acceptable to run on the hose? I don't believe it is.


I'm betting a Mercury technician that works on Sport Jets, has some kind of rig that goes under the boat and allows the water to be pumped up into the motor. I have a smaller boat with an outboard motor and I can run it on the hose indefinitely. Anyway, tell me what you think.

From the 2000 engine manual, (the Maintenance Section) is states

2. The engine may be run using the Flushing Attachment: DO NOT run the engine above
idle speeds.
3. Turn water on and flush engine block for at least 10 minutes.
4. Remove water hose and install flush adaptor plug.
5. Flush outer surfaces of pump with water stream.



In the section to winterize the engine is states,

Fill the fuel system (tank, hoses, fuel pump, and carburetors) with treated (stabilized) fuel
to help prevent formation of varnish and gum. Proceed with the following instructions.
1. Premix gasoline with a 25:1 oil ratio (32 fl. oz. of Mercury Premium Plus Oil to 6 gallons
of gasoline) to either a portable fuel tank or permanently installed fuel tank.
NOTE: DO NOT use gasoline containing any alcohol (Ethanol or Methanol)
2. Add to fuel mixture; double the recommended amount of Mercury Fuel Stabilizer or
equivalent.
3. Run the engine (using flushing attachment or in the water) for a minimum of 10 minutes
at approximately 1500/2000 rpm. Remove the fuel hose and continue to run engine until
it runs out of fuel.

So could it be that your water hose does not have enough water pressure?

Eddie

 

[buckeye_paul]

hose pressure

So could it be that your water hose does not have enough water pressure?

I wouldn't say I have fire hose pressure. However I have enough pressure and volume to run my 85 horse 4 cylinder as long as necessary. How long can you run your motor on the hose? Thanks

p.s. I have the manual.

 

[Racereddie]

How long can you run your motor on the hose? Thanks

p.s. I have the manual.

I will pull it out this weekend and give it a run then let you know:thumbsup:

Eddie

 

[buckeye_paul]

I will pull it out this weekend and give it a run then let you know:thumbsup:

Eddie

Were you able to test yours on the hose? I'm curious because I had mine on the bay yesterday and like I said before, plenty of warm water from the pee hole so I know the motor is being cooled.

 

[Racereddie]

Were you able to test yours on the hose? I'm curious because I had mine on the bay yesterday and like I said before, plenty of warm water from the pee hole so I know the motor is being cooled.

Here is what I got (all done at idle)

When I started the engine had .5 psi of water pressure and 84F (Remember I live in FL & have a smartcraft gauge)
at 1 min it was up to 100F still .5psi
before 2 min it was up to 105F by 2 min it was at 107F before it got to three it was up to 114F.

My experience here is Florida is when I am running it at cruise (4000-4500 RPM) she stays around 107F. If I suck up some seaweed she will lose speed because of lack of water flow and the temp will rise to 114F. With that in mind I shut her down.

I am trying to remember how long I would run her before I got the smartcraft gauge and therefore oblivious to the temperature, but this did seem like quite a short time to get to 114F. I would think if I ran it 4-5 minutes, mine too would give an overheat alarm.

I does say in the manual that at idle is will show .5 to 1.5 psi. Below .5 and there is an inlet restriction or internal leak. If it is above 5psi at idle then the tell-tale hole is clogged

Sorry I am not able to give an insight.

Eddie

 

[buckeye_paul]

Thanks

Sorry I am not able to give an insight.

Eddie[/QUOTE]

Thanks for the feedback. I'll just make sure I don't run very long while on the hose.