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Can you run an outboard out of the water?


Loudon's Avatar
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08-22-03, 03:57 AM   #1  
Loudon
Can you run an outboard out of the water?

Please pardon my ignorance on this one...I just got my first outboard motor(Mercury 18hp). I was under the impression that water cooled system suggests it is a bad idea to run it out of the water.

 
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Ed Imeduc's Avatar
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08-22-03, 12:11 PM   #2  
out of water

No you cant run it out of water. BUT there are some water set ups that like clamp to the motor intake and you put a hose on and turn the water on. Then you can run it. Its called a motor flusher ED

 
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08-22-03, 07:47 PM   #3  
My Two Cents

Hello: Loudon

Running any outboard motor, when it is not submerged in water or without the motor flushing device installed on the intakes with water running through it, can very quickly over heat the engine.

I would not suggest deviating from the manufacturers advice. Doing sowill prove to be harmful to the engine and very costly to repair.

There is a difference between running the engine out of the water and running it out of water.

Running the engine out of the water means while it is not in water. Running it out of water means to not supply enough water while it is running. Both will be distructive to the engine and parts that require cooling.

Running the engine while the flushing device is not installed is equal to out of the water. Running the engine with too little flow and volume of water while the flushing device is installed is also distructive.

Accelerating the engine while the flushing device ia attacted, water on, is also to be avoided. Reading the owners manual and applying the advice offered is the best and safest methods for engine maintenance and long life.

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08-27-03, 10:50 AM   #4  
Loudon
Thanks for your help guys! I may be pushing my luck, but do you know where I might find a service manual?

 
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08-27-03, 07:20 PM   #5  
bryan77
I bought mine at amazon.com.......... took about a week for shipping.....no complains really...... Here is another link for another way to purchase manual............... If you plan on keeping this motor for a long time, invest in a factory manual, the other ones cover such a big group of motors, it isnt as detailed as a factory manual, but of course they are more pricey...............

http://www.outboardrepairs.com/manuals/

 
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08-30-03, 06:14 PM   #6  
BoatCop
Another fatality from running an outboard either out of the water or out of water, is that the waterpump will also fail. All it is is a neopreme impellar located in the lower unit. It's mounted to and driven directly off the main drive shaft.

In a complete failure, small pieces of the impeller will travel up into the engine and clog the water passages. This will result in parts of the engine not getting cooling, and ultimate self destruction. Even if it get's caught in time, it takes a teardown of the engine to retrieve all the lost pieces and clear the passages. This equals mucho dinero.

Even if the pump doesn't fail completely, the vanes on the impeller could wear from the heat, sometimes becoming soft and too flexible to pass sufficient cooling water. Especially at higher RPMs. This results in overheating and, again, self destruction.

On the newer Merc outboards there is a flush fitting next to the "Pee" hole on the rear of the engine. It is usually covered by a square head plug. Merc recommends that the fitting be used, rather than the old "mouse ears" flushing device. Not sure if the smaller HP engines, like the 18 have it, but I do know that the big blocks have had them since about 1996.

I recommend that anyone who has an outboard replace the water pump impeller at the start of every season. It's simple to do for anyone mildly handy with basic tools, and at 15-30 dollars a kit, makes for inexpensive insurance.

 
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09-04-03, 05:21 PM   #7  
My Two Cents Worth

Following the instructions in the owners manual to the letter is a must. An owners manual is a must have item, regardless of costs, for any do it yourself boat engine repair and or maintenance, in my opinion.

As our resident boat moderator correctly pointed out, one failure of the impeller and or doing a repair incorrectly, I might add, will surely cost mucho dinero....

Pertaining to the flush kit or part used by Mercury Outboads, as an owner of one, the OEM instructions state very clearly that the engine must not be running when the flush kit is used.

The reason is the entire lower end, exhaust system and other parts will not be cooled without water. If that warning is in the owners manual, rest assured the outcome has already been determined by the mfg.

The flushing adapter used to install the hose, is only intended to flush out the engines cooling system. Not cool it. Nor any other parts which need cooling.

And there you have it:
"My Entire Two Cents Worth.".......

Regards, Good Luck & Safe Boating.
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09-04-03, 07:03 PM   #8  
BoatCop
Oops!

I neglected to note that the direct hose connection is strictly for flushing the system while the engine is static and not running.

Thanks to Sharp Advice for sharply correcting my omission.

 
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09-14-03, 12:35 AM   #9  
tricknbass
if i have to work on my little motor[6hp] and need to run it at the house i have a 55 gallon barrel i mount it on fill it with water then you can run it for a few just like its in the lake with out tearing it up. works for me at least

 
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11-05-04, 12:31 PM   #10  
Guythunder
Running in water

The last time I ran my troll motor 9.5 merc.in a barrel while working on carb.I screwed up the water inpeler.The guy at the shop said if you run it ia a barrel keep the water running or sometimes the exust will get in the impeler and dry it up and make it hard and thats just what happen to me after just putting in a new impeler in I ran it in a barrel to make sure it was working .Than the next day I took it fishing about 100 miles up in gods country and I launched the boat and made it to the middle of the lake and the pump quit.I learned the hard way.

 
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11-05-04, 01:41 PM   #11  
All that work on the outboards at the lake have test tanks run them in it all the time.

ED

 
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11-14-04, 10:23 AM   #12  
cane
engine maintance

Be prepared to replace the impellor once a year. It gets wet and dry over a season of use. It drys out in the storage season. It drys out in a bent position. Trash is run through it in the water. All this is just wearing it out.
If your working on or testing your motor in a barrel, that's ok. But don't run it for a long period of time.
Earmuffs with water connections forces cool water into the cooling system. But it doesn't tell you if the impellor is bad.
Another link for motor parts, boatpartstore.com

 
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11-14-04, 01:27 PM   #13  
When you put a new impellor in a motor alway check the wear plate also. Most of the time you need a new one.

ED

 
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