Flushing small 2-stoke by connecting hose-pipe?

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Babylon

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Is it possible to flush salt-water from a small 2-stroke outboard on dry land by just connecting a hose-pipe to the cooling intake/spigot? Would it damage the engine by there being no external water-resistance on the prop?

After a decade of flushing it in the club's tank (which is never changed and has become progressively polluted with ponging brackish water, contaminated with old fuel and oil dumped into it by lazy idiots), the cooling channels have become almost totally blocked and its costing me a small fortune to have this repaired.
 
I assume that you mean to connect a hose pipe to the water intake and then run the engine rather than try to do this as a static assembly?

There won't be any problem in flushing with a hosepipe as you don't need to rev the engine.

Richard
 
By way of an answer, I flush my Tohatsu 3.5hp by filling an empty wheelie-bin at home, clamping the motor to the rim, and letting it run until I'm bored with it!
 
It’s quite normal to flush larger engines this way, either with “flush muffs” or with a dedicated hose adapter that screws into a port on the engine. The manual usually tells you to remove the prop but I assume this is about protecting your fingers rather than the engine; I don’t bother and I expect neither do most other people.

So yeah, I think it’s fine as long as you can work out a reasonable way to connect the hose - normal flush-muffs will probably be too big to fit a small tender-sized engine.

Pete
 
Babylon said:
Is it possible to flush salt-water from a small 2-stroke outboard on dry land by just connecting a hose-pipe to the cooling intake/spigot? Would it damage the engine by there being no external water-resistance on the prop?

After a decade of flushing it in the club's tank (which is never changed and has become progressively polluted with ponging brackish water, contaminated with old fuel and oil dumped into it by lazy idiots), the cooling channels have become almost totally blocked and its costing me a small fortune to have this repaired.
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If it is possible to connect a hose in this way then yes you can flush the engine but probably best not to run it much above idle.
No problem with lack of resistance to the prop.
One would normally run in neutral or if it is a fixed drive take the prop off, just so you don't have a prop whizzing round all the while.

Some small outboards have a flushing connection up under the power head ........... but I am surprised you can connect a hose to the water inlet. What engine is it?
 
Yes you can do it...backflushing is a good way of removing small debris. I use a screw on end of a siiicone sealer tube on to a garden hose pipe. With the small diameter you get a good deal of pressure too
 
Where do you put the contaminated water???
I have the same problem. Cant/ won't put it down the drain. Can't put it on the garden. Too much to dispose if at the top...Too expensive to have taken away professionally
 
steve66 said:
Yes you can do it...backflushing is a good way of removing small debris. I use a screw on end of a siiicone sealer tube on to a garden hose pipe. With the small diameter you get a good deal of pressure too
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When you say 'back flushing' I really hope you're not suggesting hosing via the exhaust?

Personally, I have a couple of outboards, neither seem to work well with flushing muffs.
So I run them in a bucket.
The bigger outboard needs a big bucket and lots of water unless you take the prop off, so I do that, it doesn't take a minute.
 
Babylon said:
Is it possible to flush salt-water from a small 2-stroke outboard on dry land by just connecting a hose-pipe to the cooling intake/spigot? Would it damage the engine by there being no external water-resistance on the prop?
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I may be wrong but I don't think proper flushing is possible if the impeller is not turning as in when the engine is running. I don't think water will be able to pass the impeller if it is static.

Why not do as suggested above by using your wheelie bin or change the water in the clubs' tank.
 
In answer to the various points made:

It is a 2006 Mercury 2.5hp 2-stroke (the cheaper one with no neutral). The online manual doesn't have any technical diagrams, so until I collect it from the engineer's I won't be able to see how to bodge any tap-water hose into the cooling system.

I don't want to haul the outboard home each time in the car, fill up a wheelie-bin and dispose of salt-water into my septic-tank (no mains drainage). There is a perfectly good storage shed at my club, so I want to simply be able to flush it in-situ. In this regard, it would also be useful to flush it bolted to the outboard-bracket on the boat by connecting (my bodged adaptor) to a pontoon water-supply, etc.

Don't want to have to remove the prop either - as long as the motor is securely bolted to a bracket, a whirring prop is no more dangerous to me than taking care to walk on the pavement rather than down the centre of a motorway.

Jon

PS: Just an extra thought (it seeming sensible for the impeller to move fresh-water through the system rather than hose-pipe pressure as such): if a short length of hose could be connected to the water-intake, wouldn't it be feasible for to just 'siphon' enough fresh water from a bucket to flush the innards?
 
Yes it's easy......silicone tube end connected on to a hose pipe back flushed through the rubber tell tale hose. As this is a sealed system I have absolutely no idea how this could flood the engine
 
steve66 said:
Yes it's easy......silicone tube end connected on to a hose pipe back flushed through the rubber tell tale hose. As this is a sealed system I have absolutely no idea how this could flood the engine
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How would the back-flushed water get past the impeller pump?
 
SAMYL said:
I may be wrong but I don't think proper flushing is possible if the impeller is not turning as in when the engine is running. I don't think water will be able to pass the impeller if it is static.
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Correct, but he’s planning to run it. Just wants to use a hose instead of a tank, which as mentioned earlier is the norm for larger engines bolted to the transom (can’t balance 100hp on top of a wheelie bin :) )

Babylon said:
The online manual doesn't have any technical diagrams, so until I collect it from the engineer's I won't be able to see how to bodge any tap-water hose into the cooling system.
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My 2.2 Suzuki has slots from outside straight into the impeller housing just ahead of the prop. There isn’t an “intake system” as such that you might be able to connect into.

Babylon said:
I don't want to haul the outboard home each time in the car, fill up a wheelie-bin and dispose of salt-water into my septic-tank (no mains drainage).
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If you fill up the wheelie bin with salt water then why bother with any part of the process? :)

Babylon said:
if a short length of hose could be connected to the water-intake, wouldn't it be feasible for to just 'siphon' enough fresh water from a bucket to flush the innards?
Click to expand...

I’m not convinced that the impeller would prime and be able to suck in water from a bucket standing nearby. However, if you were to hang your water supply from whatever the engine is clamped to, the modest gravity feed should do the job. I’m envisaging some kind of funnel (even an upside down bottle with the bottom cut out) that you could top up from a bucket, if needed, while the engine is running.

Pete
 
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