Looking for Rabbit Ears...

G

Gone Fishin

New member
As part of my OB engine maintenance, I would like to start flushing the engines after pulling out of the lake. I found the following information that refers to "Rabbit Ears" as a device for engine flushing. I failed to locate one when searching the internet and marine sites. Thanks for your assistance.

"To flush the engine you will need a set of "rabbit ears" (two flexible rubber seals connected with a metal clamp). Simply slip this apparatus onto the lower unit where the water is picked up and attach a garden hose. Start up the engine and let the water pump do the rest. (Be sure to stay clear of the prop and make sure no one tries to shift into gear)"
 
Although I have never heard these things called "rabbit ears" I have used them on every outboard I have owned. Properly attached to the engine they provide a sufficient supply of water to allow you to run the engine for a while out of the water. Not only is it good for flushing but I also heat the engine and engine oil prior to changing it.

I can't imagine these things will be hard to find, and they are not expensive at all.
 
I got a set for under 10 bucks at West Marine. They work great. Look under "Motor Flushers". Use at idle only.
 
I have heard them referred to as "ear muffs" but never "rabbit ears"!! GI Joe's will certainly carry them. We used ear muffs to flush our Honda 40s on the CD22 after every outing. A note however - on the Honda BF-150, there is a place to connect a garden hose, and the manual says NOT to run the engine while flushing with the hose.
 
What's with the "Idle only" bit? with the water pressure I have (or I should say our water supply has) :oops: I could run at WOT and still have it spraying ot of the hose fittings from overpressure.

Merv (gotta run)
 
The Honda 150 Manual for the 2007's says to flush with the engine OFF only... DO NOT RUN ENGINE TO FLUSH is a big warning. I think this depends upon each individual engine's design.

John
 
My Honda manual for the 2006 BF40 indicates only usage of the plug and adaptor and simply says "run at idle for 5 minutes" with no dire warnings other than to watch in case the overheat light comes on.

My thought is that with full water pressure applied to the main inlets to the point where it is spraying out all over the place would give at least as good circulation as when in water. So if I get that plus a good tell tale stream I should be able to run at any speed. Not that I need to, but.... it'sometimes useful to see that they will run smoothly above idle...

Merv
 
Grumpy,
I have read that you risk having the motor run away from the lack of resisitance provided when your prop is in the water vs. using "Ear Muffs". That is why you should not run above idle when using them. It sounds as though bigger motors and different models may have different requirements. I had noticed the poster had a 16' and since I have the same boat I replied. I did not say to run a large engine with earmuffs either. I will be more careful in the future.
 
JT,
You are probably right. I can certainly see that if you just opened the throttle wide on a carburetted engine with no load, you could easily overspeed it. Don't know what an EFI would do.

I just like to blip the throttle to "clear their throats" after running at idle before I shut them down.
Probably doesn't help anything but I do it anyway. (and it sounds good !!)

Merv
 
Grumpy":mjzlx3za said:
My Honda manual for the 2006 BF40 indicates only usage of the plug and adaptor and simply says "run at idle for 5 minutes" with no dire warnings other than to watch in case the overheat light comes on.

My thought is that with full water pressure applied to the main inlets to the point where it is spraying out all over the place would give at least as good circulation as when in water. So if I get that plus a good tell tale stream I should be able to run at any speed. Not that I need to, but.... it'sometimes useful to see that they will run smoothly above idle...

Merv
Click to expand...

I was talking to a Honda dealer about flushing. I *think* what she
said was to not run the engine when using the direct engine hookup.
The reason is that the water flow is not going through the pump and
so you could burn it up. At least on some models. And on some
models, the manual is *wrong* -says it's OK to run using the flush
hookup.

Now, she told me this day I bought the boat, along with lots of other
stuff. Someone can probably add to this point. I have a BF-90, but
she was also talking about 40s and wasn't sure which had the problem, or possibly both.

As for using ear muffs and idle: well, I wouldn't rev it a bunch, but
certainly a faster idle is OK. Besides, if it's cold out, what choice
do you have anyway. Just check the water temp coming out of the
engine. If the water is rather hot, then you might not have enough
flow.

Most ideal is to get a garbage can under the engine, fill it to the
boat's waterline and run that way. This way, the muffs can't
fall off, no one can kink the hose, etc. I usually have to pump the
can out, but I have a manual bilge pump, so this isn't too hard. 30-40
gallons doesn't take long to pump.

Make sure you put enough water into the can. Needs to go to the
boat's waterline, not the top of the plate.

Mike
 
''Most ideal is to get a garbage can under the engine, fill it to the
boat's waterline and run that way. This way, the muffs can't
fall off, no one can kink the hose, etc. I usually have to pump the
can out, but I have a manual bilge pump, so this isn't too hard. 30-40
gallons doesn't take long to pump.''

Mike


Wouldn't it be easier to siphon the water out?

Joe.
 
Grumpy,

Do you sit in your car and run the engine at full throttle in neutral?

Running an outboard (or car motor) at speeds above idle without a load on it(meaning being in the water with the motor in gear, boat moving freely at speed) can result in exploding your motor with rods and other parts shooting out through the side of the crankcase.

Blipping the throttle on an idling outboard either in the water or on a flusher can cause damage and premature wear.

It does no good and doesn't 'clear the bores'. Outboard carbs do not have accelerator pumps like car carbs have. Outboards don't have foot throttles and rapidly opening and closing the throttle is not intended or designed for.

Hook up the hose to the flusher, clamp the rubber cups over the water inlets on the lower unit, turn on the water, start the motor, idle 5 minuets in neutral, shut off the motor, shut off the hose, remove the flusher, remove the hose from the flusher and you are done. Extended running on a flusher does no good.

An outboard is designed to be operated with the lower unit in the water. The water provides back pressure on the exhaust system. The motor is designed to work that way. Running the motor on a flusher on land is just to wash out salt, silt, or sand from the cooling system.

Always read and follow the instruction in your owners manual.

Otherwise you might find yourself contributing to the "outboard mechanics retirement fund"! LOL
 
I just purchased a new C-Dory 16 with a Honda 50. The dealer installed and aftermarket hose for flushing the engine. It exits the engine the same place the control cables do. He said DEFINITELY DO NOT RUN THE ENGINE WHILE FLUSHING. I know the manual says you can but according to the dealer who seems quite knowledgeable the engine doesn't get adequate water to the pump. My boat is kept in a boat lift so "rabbit ears" aren't and option. I can't remember the name of the stuff (Salt Away?) but as recommended by a friend I've been using and in-line flushing device and this chemical which supposedly dissolves salt. Time will tell as the water I'm in is as salty as it gets. My previous Mercury didn't hold up well at all in the environment.
 
Looks like a classic "he says - she says, and the manual says".
IF I obeyed my manual as Larry H suggests I would be using the flusher plug and running at idle which contradicts what the dealer is telling you.

I tend to agree that using this plug does not get water flow to all the vital parts. Hence I do not use it.

Good point about the back pressure on the exhaust Larry. hadn't thought of that one.
But as I said, I don't advocate doing anything other than idle with Rabbit ears anyway, just said you can, with caution.

I do use the Salt Away stuff though for washdown and occasionally for engine flush. Seems to work well on the boat and windows (wish it would work on my computer) and hopefully it does some good to the trailer. Not sure of the real benefits for the engine as it seems to me that 5 minutes at idle would be more than enough to get any salt off a piece of machinery that was designed to run in salt water. maybe if you live in a hot climate and the motor really dried out before you get to fluch it then there could be salt caked/baked on which might be harde to remove.
Anyone got any facts or figures to compare ? Wonder how long a typical OB would last if the boat is used in salt water and never flushed (except maybe at service intervals).

One thing I would add is that I bought the round ears, and you have to be really careful to fit them for minimum leakage. I think the rectangular ones would fit better to the shape of the intakes.

Perhaps the best solution for us in the PNW is to launch in Lake Washington and drive around to a convenient restaurant once a week. Gets my internal pipes taken care of as well.

Merv
 
Sea Wolf":hid15tz6 said:
''Most ideal is to get a garbage can under the engine, fill it to the
boat's waterline and run that way. This way, the muffs can't
fall off, no one can kink the hose, etc. I usually have to pump the
can out, but I have a manual bilge pump, so this isn't too hard. 30-40
gallons doesn't take long to pump.''

Mike


Wouldn't it be easier to siphon the water out?

Joe.
Click to expand...

I dunno. It's not hard to pump. I have one of those pumps that looks sort of
like a bicycle pump with a vaccum cleaner hose on the end. It moves a lot
of water.

Mike
 
Outboard water pumps, a lesson:

The water pump in the lower unit of an outboard is located near where the lower unit is bolted to the leg.

The water pump is a rubber impeller inside a stainless steel liner in a plastic housing(in the old days it was an aluminium housing). The impeller turns whenever the powerhead turns. In gear or out of gear.

The rubber impeller rubs the inside of the SS liner and if it is dry the impeller will heat up until it melts! The impeller is lubricated by the water inside the pump.

Starting an outboard dry will damage the impeller is as little as 10 seconds. When replacing an impeller, it should be lubricated with a water soluble grease. (Hand cleaner) or 2-cycle oil(doesn't hurt rubber). Avoid using motor oil.

I think the flush plugs located at or near the powerhead inject water above the water pump and flusher muffs (rabbit ears) puts the water into the water pickups (below the water pump) used by the motor when its in the water. The flush plugs were added to the motors so that the motors can be flushed with a hose without running the motor.(in the slip or on the trailer without running the motor and bothering the neighbors)

I am not a Honda expert, so specific Honda advise is best obtained elsewhere.

I hope this info helps owners to not contribute to the "mechanics retirement fund" excessively! LOL

Good boatin' to yah!
 
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