'Outboard Muff'

[Keith Hart]

Hi there

I mentioned in an earlier post that I flushed my engine out with fresh water after use. We have a plastic barrel with a 'transom' fitted. I've just read an article in Rib International Online ( www.ribmagazine.com ) that spoke of this but mentioned an 'Outboard Muff'. What the heck is one of these?

Cheers

Keith Hart

[Scubakid]

This is two rubber/plastic cups attached together by some springy material (normally metal) one has a hose connecter fitted you then slip this over the water intake in the leg turn the water on and start the engine. Hope this helps

John

[Rannsachair]

They attach over the water inlets of the outboard- connect a hose and you can then flush the engine.

[Brian]

My last two Honda 4-stroke engines (75 and 130 hp) both had a rubber-capped housing inside of which was a brass(?) nozzle onto which you could attach a standard "Hozelock" type connector and thus a hosepipe.
This helped me, being permanently marina-moored, as Ididn't have to lean out too far back to connect up and could leave the process while I carried on with something else.
Maybe other engines have this type of fitment too?
Cheaper than buying muffs.

[Alan Mckewan]

At the local Yacht club we call them "ear muffs". They are a great piece of kit; we always run the rescue boat outboards on them before each launch to warm them up and make sure that they will start easily after launching. They also get a quick run after lifting out to remove salt deposits and check the tell-tale hole is clear.

[Scubakid]

My honda 130 has an attachment to flush the engine but as this is attached to the 'head' I am never to sure if I should run the engine as there is no water supply to the pump which may be running dry. does anyone know the answer ?

[Brian]

I don't know the precise answer to your question.
Is there a Mr. Honda out there?
However, why run the engine?
My understanding is that injecting fresh water through the flushing nozzle permeates all the bits that it is supposed to wash out and then exits BOTH through the normal water exit port when running at sea, and through the rear of the prop boss.
I used to keep my boat permanently on the water in a marina and after lifting the engine up to a position clear of the water, flush it through (engine not running) and then leave it.
Did that for a few years with no problems.

[Charles]

Quite right Brian, the new generation outboards have the hose fitting for flushing the engine with fresh water, you do not need to run the engine.If you inssist on running the engine just ensure water is exiting out the port.

[Alan Mckewan]

All the recent big Suzuki 2 strokes such as the 100 V4 have a flushing inlet high up on the side of the main engine cowling. This is fine if all you want to do is flush the engine, but we always run our club engines for a while to make sure they are running OK (and warmed up) before launching. This port only puts water down into the oulet side of the water pump, so I dont believe it would be safe to run the engine on this flushing point; we use ear muffs so the pump is used as well. I think the same applies to the Hondas.

[Keith Hart]

My 15 hp Mariner is 'officialy' flushed out by removing the prop and connecting a hose. You then run water through the engine.

I did not want to take the prop off unless absolutley necessary. I just feel that I would risk making it loose in some way then loose it when out in the boat - a sort of 'if it aint broke, don't fix it'.

I simply drop the engine into my large plastic barrel with home made transom, which is full of fresh water, then run the engine for a couple of minutes untill it is nice and warm and the water is comming warm from the drain hole at the top.

This is a simple solution to the problem which means that it actually gets done when needed.

I suppose that this would not be practical with your bigger engines?

Cheers

Keith (feeling flushed) Hart

[batfalcon]

You are absolutely right with your method. The same one could be carried out with large engines, BUT. You have to put the barrel under the engine instaed of the engine in the barrel. Then you must remove the barrel and this seams to be rather difficult with the barrel filled with water. So you have to drain the water from the barrel, prior moving it. No question it's the best cooling method among all. Because of the difficulties on practice most of us use the muffs instead.

[Jari Hjerppe]

I use exactly the same method with my 15 Merc (similar OB, only with Merc stickers and black colour). The water intake is under the cavitation plate and it's not easy to fit the "ear muff" type flushing system.
By the way, I would recommend that you remove the prop at least once a year and clean and grease the prop shaft with suitable grease. That will protect the prop shaft against the corrosion and prevent the propeller to stick to the shaft.

Jari

[Keith Hart]

Hi I remember that over the past couple of years there have been discussions about 'winterisation' etc. and engine flushing. I've just found this picture of the device I use so here it is. By the way guess who made it? Yup, Charlie.

Keith (good old Charlie) Hart

[Garygee]

Hi folks

Now this is where I look a fool

Does anyone flush out inboard engines, or do they have enough protection in the form of anodes on the saltwater side of the cooling system.

I know the the engine is cooled via a heat exchanger but would there be any benefit to fitting a flushing system to the saltwater side of the heat exchanger ?.

Even if the RIB is kept in a marina, which mine will be (when it arrives ) freshwater hoses are usually available.

Would it help the lifespan of the heat exchanger or is there not a need for flushing ?.

Also on the subject of anodes is it better to keep a outdrive (bravo 2) fully submerged and have all anodes in the water or fully raised where the prop etc is out of the water ?.

Regards Gary

[matiboy]

I see no reason why a boat sitting in a marina cannot still be flushed using muffs if you have a freshwater hose available...

At the end of the day if you towed your inboard back home on a trailer, what would you do..... flush the engine out on a hose I suspect

place the hosed muffs on outleg, run tap and lower leg back into water to flush.....In my humble opinion this can only be of benefit

With regards to lifting the leg when sat in the marina, I would think this is a must as it will quickly get fouled up otherwise

The yaghty people hang sacrificial anodes from their boats and this may be something that you could consider, hanging a sacrificial anode from the leg ??? Worth a thought

[Brian]

Garygee
I suggest you take professional advice on this.
Some points:
1. My boat is always in a marina and never out on a trailer except for repair/maintenance.
It has never been flushed. Doesn't seem to need it?
2. There is a flushing point on the leg but the strong probability is that this will not supply sufficient water to the engine. I THINK (but dont know) that the water entering through the leg also circulates around the engine to cool it. And a big inboard requires A LOT of cooling.
3. The engine and the leg have quite a lot of sacrificial anodes designed in. As long as these are changed/refreshed regularly you should be OK.
4. Certainly on my boat you cannot raise the leg clear of the water. A big inboard diesel and a heavy leg combine to ensure the whole of your leg is well below the waterline. So even if you do flush-as soon as you detach the hose, the leg is automatically below waterlevel again.

As I said-get professional advice (your boat builder MUST give you this advice for free). Mine said " As long as you have the boat properly serviced you do not worry about such things".

[dbillyboy]

Oh bugger, flushing? Muffs?? I'm lost already and I am just about to get my first engine to power my sib!!
TLS.

[Richard B]

Flushing outboards with raw water cooling (and inboards with raw water cooling) is much more important than flushing inboards with a heat exchanger. Reason is that your heat exchanger can be serviced much more easily than the waterways in the block of a raw water cooled engine. Yachts and motor cruisers don't ever get flushed - the intake is usually under the hull near the keel. Our hard boat has never been flushed. Unfortunately some inboards are raw water cooled (mercruiser petrols, I think) and need need flushing or else they eventually die!

[Garygee]

Some interesting replies.

The engine arangement means that the cooling does not go through the leg but has a seperate cooling intake. This means I could shut of the salt water intake and open a flushing point, closing both and trapping fresh water in the heat exchanger if required if benificial.

The enine is fresh water cooled (Yanmar 240hp), but was curious but unsure as I know that you need diferent anodes in fresh water and so it could have been worse in freshwater with the wrong anodes then in salt water with the right anodes.

This was also the reason for the outdrive question, I know the drives are well protected (Bravo 2) but would like to have as much out of the water as poss to prevent fouling BUT in rasing the leg and no dought lifting some of the anodes out of the water would the be sufficient anodes left in the water to do there job.

Anyway as Brian said the manufactures must give you this info, but would the engine manufacture(Yanmar) out drive manufacture(Mercruise) of the boat manufacture (Ribcraft).

Also on anodes was shocked the UK prices for anodes £65+VAT a set
Then when I looked at the states, got quoted $35. a set plus $30-$50 shipping.As i am told I may need 2 sets a year as the boat will be in the water all year I plan to order a few sets from the states, or does anyone know somwhere in the UK whos prices are realistic.

US Prices 5 sets $35*5 +$50 P&p =$225 (£145+ VAT approx)
UK Prices 5 sets £65 325+VAT

(me thinks were getting ripped off again )


Anyway will find out when it gets delivered (I hope)

Regards Gary

[Brian]

Well both the leg and the Yanmar engine are imported and supported by E P Barrus of Bicester, Oxon. whose techies are very helpful.
Ask your boat manufacturer as well. Why not?