Outboard flushing

[Birdnest]

My Honda 115 has a flushing port on the back side that allows you to attach a garden hose via an adapter to flush your lower unit. You are to do it with the engine off for 10 minutes.

My dealer told me to use the "head phones" with the engine running.

Is one vs the other a more thorough flush. I tend to lean toward the safer non running approach as to avoid any "head phone mishaps".

Any thoughts?

Birdnest

PS It is very painful to watch you guys rough up these big 'buts while I am getting a feel for my boat. [img]graemlins/dork.gif[/img]

[Tacklebuster]

Good question, before I bought my inboard I had an outboard and wondered the very same

[TyeeTom]

A good question. I also have a Yamaha with the garden hose attachment and use it every time I've been in the salt. However, the owner's manual says to use earmuffs to flush before storing for the winter. I asked a dealer about it and he said the manual was probably wrong. The question is, does the flushing with earmuffs do more than the hose attachment? Anyone know?

[Birdnest]

My manual doesn't even mention the head phones system.

Birdnest

[Pitch Pocket]

Doesn't hurt to be thorough. Do both.

[Mello-Yello]

I too have a Honda 115. I asked the same question and here is the explanation I was given.

Using the earmuffs is advised because it flushes the entire engine. Running it for 10 minutes is a ballpark figure. You need to run it long enough for the thermostat to open, so that the engine will be flushed completely. This doesn't typically take 10 minutes, rather maybe 5.

The garden hose hookup is to be used if you moor your boat in the water. This flushes everything but your engine. I believe the purpose was to keep slime from growing in your cooling system, and prevents you from having to run the motor when moored.

One note on using the ear-muffs. Don't run your water at a very high volume. Your motor has a pump, which will pump the water you supply through the cooling system. The engines water pump doesn't create very much pressure, certainly nowhere near what your home water system has. If you crank on the water at it's existing pressure (typically 40-60psi), you're over-powering the water pump and could cause damage.

Run your water only enough to ensure water exits from the small weep hole at the base of the engine. The flow from this hole is only an indicator that your pump is working. It serves no other purpose.

M-Y

[Birdnest]

M-Y,

Thanks, sounds like all good info.

Birdnest

[Lepper]

Mello left a good explanationg.. now the next thought.. does it take as long to open the thermostat when you do it immediatly after you have pulled it out of the water?? like the motor is alreayd nice and warm??

[Mello-Yello]

Well, since a thermostat is controlled by a bi-metalic spring, which relaxes when it's warm, it would make sense that an already warmed up engine would warm the water around the thermostat sooner.

So, yes...I'd think it would

[SouthCoastStu]

On my Honda 5hp, I use the adapter because I would have to remove the prop every time I flushed the motor if I wanted to use the rabbit ears.

The dealer's mechanic told me to use the rabbit ears over the adapter (which I do on my Honda 90).
He also told me you should run the gas out if it's going to sit for any length of time. Something about getting varnish build-up in the carbs. Does this sound right?

My routine is to flush until the motors run out of gas. Is this OK? Comments appreciated.

Good tip on the water pressure MY, I'm going to back it off a notch or two from now on.

[Lepper]

Running gas out of a carberated engine is allright.. But with the new electronic fuel injection systems I believe you are not suppose to run them out of fuel.. The fuel lubricats everything.. and when you run it out it actually causes damage.
dave

[Mello-Yello]

On my Honda 8hp, I have to take the prop off to install the flush unit. It's a funky little rubber doohicky w/a wire clip. Major pain in the buttox. After being in salt water, even though my kicker hasn't been run, I jam a water nozzle in the water intake and hold it there. After about 20 second, water starts coming out all the ports. My thinking is, even though I haven't used the kicker, it's very likely that salt water has entered the lower unit (back-trolling against the current, waves, etc). If I do run the kicker in salt, I'm able to slip an empty rubber garbage can under the motor, fill it with water, and run the engine to flush salt out of the engine. More often, I'll back the boat in the river on the way home and run both engines in the fresh water (provided the ramp isn't silted up too bad...muddy water isn't good flush water).

As great as Honda engines are, I don't know what they were thinking when deciding to have a flush system that requires the prop be removed.

It used to seem like common practice to run a carb out of gas if it isn't gonna be run for awhile. Before I'd do this as a solution for preventing varnishing your carb bowl...I'd suggest you do this; Run the motor w/the gas line unplugged. When the engine stalls, pop the hood and pull the drain plug off your carburetor bowl. If nothing comes out, your doing ok. If gas comes out (this is often the case), you're wasting your time. A lot of engines will die before you've spent all the fuel in the bowl. Hence, the remaining fuel will varnish on you.

Today's gasoline doesn't have a very long shelf life. Many mechanics recommend you periodically add fuel preservative when you fill your tank. Since a smart boat owner rarely lets their tank get below half full, you end up with some pretty old gas mixed w/the new gas. Adding new gas doesn't make the old gas new again. If you've added a preservative recently, I don't think I'd worry about varnishing your carb.

Lepper's concern of losing your lubricant only pertains to two-stroke engines, as the oil mixed with your gas is your engine's only source of lubrication. This isn't a concern w/four-strokes.

M-Y

[ 05-10-2003, 10:55 PM: Message edited by: Mello-Yello ]

[Birdnest]

That is funky that you guys have to remove the prop for your kicker. My 9.9 doesn't have that same issue. M-Y thanks again for your input.

Birdnest

[Mr. Fisherman]

I bought a motor flushing bag and wouldn't be without one. In addition to flushing the motors (Main and kicker) without any special adapters and getting a complete flush I don't have to worry about over pressurizing the head gasket. It is easy to see when the thermostat opens as it utilizes the systems water pump. The neighbors like it because it muffles the engine and puts the right back pressure on it so I can tune and work on the boat at home without dragging it to the river or a lake. It has already paid for it's self. I paid just under $80 for it, money well spent and I highly recomend them. It rolls up and dosen't take up much space and it is far easier to use than a trash can. Ever try to empty a 50 gallon trash can without being able to move it? Not fun.

[Stratocaster]

I have a Honda 2003 40hp. I use a hose adapter that screws into the leg after removing the "wash" screw. It then says to tape over all (3) water intakes, i guess to create suction.The local Honda dealer was unaware of this taping of the intake ports, must be a new thing.

[Chilly one]

Mello-Yello, in regards to your 8hp. Hondoo you shouldn't have to remove the prop to flush. Attach the flushing fitting w/clip with hose already screwed on by simply bringing the hose somewhat from the front to the rear thru the blades on the prop. No problem. I've owned 4 8hp Hondas and flush evertime and this will work. make sure you get the opening w/screen on the motor covered with water flow. Don't need alot of pressure from hose. One thing to keep in mind tho, the barbed end of the brass fitting on the flusher attachment can wiggle a bit so make sure it is tight with rubber part of flusher. Good luck! Chillyone......ps. I think Honda could have designed a better flush as well.