Flushing engine after use - how do you do it?

[robhc1000]

Morning,
How do people flush their engines after use? I have been running mine in a deep bucket but wondered if other people had a better way of doing it? I see you can get muffs for modern (compared to seagull) engines which go either side of water intake, i tried to put end of hosepipe up into water intake on my 102 but did not work and did not want to run engine dry of course.

[phil]

Fortunately have a lake on the way back from salt water, back trailer in run motor on boat for a few minutes if it's not busy at the ramp.
Or run in half of a 200 liter plastic barrel at home that I use to run motors in.
Forties and Centuries can obviously be back washed with a hose and proper fitting.

[Stelios_Rjk]

A 102 could be flushed undoing the nut that holds the pipe on the top of the block. Over there you have to mount a garden hose and that's it. But you can't start the engine this way as the water flows the opposite way through the engine.

On square blocks engines is easier as you can fit a 5/16 (8mm) pipe (copper or waterver) in the water outlet and mount there the garden hose. Again you can't start the enigine for the same reason.

In a deep bucket you can remove the prop since it's not clutched your engine. Leaving the prop on may lead to poor or no cooling water reaching the cylinder. That's becase of the mad water flow in the bucket.

I prefer flushing the engine running for 15min in a deep bucket as the heat may help remove more salt from the block. But I don't know if that really helps (remove more salt) or not.

[1650bullet]

You don't have to run the engine when flushing. As stelios said, Undo the nut that holds the water outlet pipe on top of the engine block between the fuel tank and flywheel. Push the end of your hose over the threaded end and turn it on for a few minutes. Once its all flushed you could squirt it bit of WD-40 down in the threaded area to leave soak in the water channels in the cyl block. Wash the whole motor down and spray the whole engine top to bottom with WD-40 to prevent any corrosion.

[Keith.P]

Not so practical with a brass water pipe on a 102 and if you dislodge any rust, it will sit in the water pump for next time.
Wouldn't running in a clean tank of water do the job, with a hot cylinder head drying out any residual water, better than a cold water flush.

[Gannet]

Yes, I think a hot flush is possibility the best method. And I agree that a dewatering oil (eg WD-40) inside the water passages is also very effective, as it is on the outside.
I would imagine that if there is not enough heat to completely dry the water passages then it would surely stay damp for a very long time. I usual pour or squirt dewatering oil into this area, thinking that it will soak into the rusty surfaces, displacing water and preventing corrosion. I do this by rotating the engine so that I hope all internal surfaces are covered. There is also the potential of later pouring/squirting in some corrosion protection oil, for better and longer (ie over winter) protection.
As our outboards, for the main, are used just occasionally, I would expect that the corrosion that our outboards suffer is predominantly during storage.
It is obviously not possible to undo the corrosion that has occured over the last 40 or 50 years, but I think it is possible to very significantly reduce future corrosion.
Jeremy

[Stelios_Rjk]

Another sequence that may be too "scientific"

A hot flush
Place the engine upside down and fill the water jacket with vinegar, leave it overnight
A hot flush
Leave it to dry
Place the engine upside down and fill the water jacket with diesel or WD40 in case you buy it in large quantities.
Leave it this way for a couple of hours, then it's ready to store it. The disel or WD40 will spill on the floor of course when you turn the engine to it's regular possition.

[Charles uk]

Any flakes of rust falling out of the cylinder after this treatment will taste just like Salt & Vinegar Crisps honest!

[Stelios_Rjk]

I fill lately the water jacket of a forty as I couldn't undo the head and indeed many tasty/rusty flakes come of! Seems to work at some point!

[Keith.P]

For the time it takes to do all that, you could have pulled the cylinder off the motor and put it in the airing cupboard.

Or you could drain and flush the fuel system with WD40, Drain the gearbox of all oil and water and flush with WD40, flush water system with WD40, wrap up in an electric blanket over the winter obviously with the light on, with radio four playing in the background, hoping that it lasts the winter without a serious complex.

Seagulls have lasted this long without much maintenance and they do need a little TLC admittedly, but my motors are a lot better off since I started collecting them and they don't get pampered.

[Stelios_Rjk]

[Collector Inspector]

I have a 200 L drum full of water soluble cutting oil mix. Milky white.

If I have a doubt with flushing away or a motor restored to go on a back rack for many years I run in that drum.

Other names are Soluable Oil and Steam Oil.

Just a thought for long term internal protection.

B

[robhc1000]

So undo pipe and flush through with hosepipe on threaded end?

[1650bullet]

So undo pipe and flush through with hosepipe on threaded end?

That's it. Your garden hose should be a tight fit over the exposed threads on the stub. Turn on your hose and watch all the water squirt out the water inlets. Smear some marine grease around the threads as you fit the water outlet back on. Ive had a look at your motor and see there is a bit of surface all over it. If you have a pressure washer, spray a heap of degreaser all over your motor top to bottom and give everything a good hit. Give it a good blow dry if you have got an air compressor. and spray top to bottom with WD-40 and leave it dry. Its the best way to preserve your motor.

[robhc1000]

So undo pipe and flush through with hosepipe on threaded end?

That's it. Your garden hose should be a tight fit over the exposed threads on the stub. Turn on your hose and watch all the water squirt out the water inlets. Smear some marine grease around the threads as you fit the water outlet back on. Ive had a look at your motor and see there is a bit of surface all over it. If you have a pressure washer, spray a heap of degreaser all over your motor top to bottom and give everything a good hit. Give it a good blow dry if you have got an air compressor. and spray top to bottom with WD-40 and leave it dry. Its the best way to preserve your motor.

Thank you, planning to take boat out next week so will pressure wash it after that. I hope to give motor a good cleanup and refurb in the winter so will take before and after photos.