Flushing an outboard ?

[Billfo]

What is the purpose of "flushing" an outboard motor & could someone highlight that procedure ?

Thanks for the help..
(Can you tell this is the first outboard I've had to work on)

 

[turbinedoctor]

Re: Flushing an outboard ?

Hello Bill. When asking about flushing an outboard I am quessing you are referring to the cooling system. Generally flushing is done after a trip out on the water to clean out the cooling system. Mostly it is done when the motor is used in salt water since salt water will corride aluminum when left in it for extended periods of time.

Steps to flush engine. Using a good set of muffs, which go around the water intake on the lower unit, apply just enough water pressure to get a small amount leaking around where the muffs fit on to the lower unit. Start the engine and make sure you have a pee stream out of the tell tale hole and still have a small amount leaking around the muffs. I use a inline water valve with a 10 foot hose between it and the muffs. I put the inline valve over the gunnel so I can turn on and off the water and also adjust the flow while running. Let the motor run for about 5 minutes then turn the engine off, remove the muffs, let the engine drain and your done.

Personal note, I like to pull the fuel line to run the fuel out of the carbs during the last of the engine flush and stop the engine when it starts to stumble. This keeps the carbs from leaking when i tilt it up and helps prevent carb gum from building up.

Durwood

 

[Billfo]

Re: Flushing an outboard ?

Thanks for the reply.. Yes cooling system, I want to flush all the possible crap out BEFORE I change thermostats & water pump/impeller ..

Hello Bill. When asking about flushing an outboard I am quessing you are referring to the cooling system. Generally flushing is done after a trip out on the water to clean out the cooling system. Mostly it is done when the motor is used in salt water since salt water will corride aluminum when left in it for extended periods of time.

Steps to flush engine. Using a good set of muffs, which go around the water intake on the lower unit, apply just enough water pressure to get a small amount leaking around where the muffs fit on to the lower unit. Start the engine and make sure you have a pee stream out of the tell tale hole and still have a small amount leaking around the muffs. I use a inline water valve with a 10 foot hose between it and the muffs. I put the inline valve over the gunnel so I can turn on and off the water and also adjust the flow while running. Let the motor run for about 5 minutes then turn the engine off, remove the muffs, let the engine drain and your done.

Personal note, I like to pull the fuel line to run the fuel out of the carbs during the last of the engine flush and stop the engine when it starts to stumble. This keeps the carbs from leaking when i tilt it up and helps prevent carb gum from building up.

Durwood

 

[milehighboater]

Re: Flushing an outboard ?

Muffs are quite cheap, I have had better luck with the set that runs though the lower unit and stays together with a wing nut. The clip style does work well but I often am doing this by myself and having it held into place by a long bolt gives me more piece of mind then the clip style where there is more trial and error. Either one works well and can be picked up from any marine store. Just a reminder keep the motor under 2K most of the time the muffs can't supply enough water to keep the motor at a high RPM for very long.

 

[turbinedoctor]

Re: Flushing an outboard ?

Well that should do what you want then.


Durwood

 

[Billfo]

Re: Flushing an outboard ? ( BACK FLUSH )

Re: Flushing an outboard ? ( BACK FLUSH )

I have a good set of muffs, I thought I seen a pic somewhere , where you hook up a garden hose directly to the motor someplace on the aft end of the powerhead.

EDIT: This is the statement that confused me.

****I back flush it thru the hose connector on the lower unit once a year as normal maintenance.

Well that should do what you want then.


Durwood