Engine Flushing

[vangrady]

My boat has two '2000 Yamaha 250 SX TXRY's that are running in salt water. I have heard that there is a method one can use to fresh water flush these engines without using the headphones or muffs. Is this possible and if so, how do you do it?
Many thanks.

 

[catch22]

On the port side of the engines, just below the cowling, there is a black garden hose fitting, (female) with a short rubber line on it. Simply un-thread, attach your garden hose and flush away. You'll see water exiting the tell-tale, (pisser). Run the water for about 3 to 5 minutes. Don't run the engine and don't forget to re-attach the the fitting when your done, (don't laugh... many people have done it... not me of course, cough, cough).

 

[vangrady]

Thanks Catch 22. I will have a look on the weekend.

 

[vangrady]

I forgot to ask you if the engine should be tilted when flushing or in the running position?
Thanks again.

 

[JUST-IN-TIME]

either way is fine

if you tilt the water will be still stuck in the lower unit

 

[catch22]

I forgot to ask you if the engine should be tilted when flushing or in the running position?
Thanks again.

Just to expand on what just in time said...

The issue of trapping water in the lower area of the outboard, is a concern in freezing temperatures. As a rule, during cold season use, (or layed up for winter storage) you want the outboard tilted straight down, (verticle) to allow any water to completely drain. If the motor was left tilted-up, trapped water will freeze, expand and cause severe damage.

As far as flushing right now, (during warm weather) I don't really know if there's any advantage either way, (up or down) but... if I were trailing, I would flush with the motor down. In a slip, I've always flushed with it trimmed up.

 

[JOSH S]

On yamahas I have owned in the past yamaha recommended flushing in the tilted position if the engine is not running and in the vertical postion if the engine is running. BTW you can run the motor when flushing through the port. Just as previously stated though be sure to lower the motor for winter storage.

 

[CJBROWN]

On yamahas I have owned in the past yamaha recommended flushing in the tilted position if the engine is not running and in the vertical postion if the engine is running. BTW you can run the motor when flushing through the port. Just as previously stated though be sure to lower the motor for winter storage.

Hmmm...I would caution on this. My understanding is that you CANNOT run the motor with the flush port - there isn't enough water for the impellor to pump through the engine and overheating is the result. Only run with muffs, and even then yamaha's have a reputation of overheating unless you have the twin hose bib style - a hose on each side of the muff. Running in a barrel is by far the safest, or one of those new-fangled water bags for flushing.

The most important thing is that they get flushed if they have run in saltwater. Salt will crystalize in the water jacket and eventually clog, just like an exhaust manifold of an inboard or I/O. Only the passages are a LOT smaller in the outboard so it's critical.

 

[vangrady]

Thanks guys for all your helpful input. My boat is kept year round in salt water and in our parts we do go below freezing for a few months of the year. From what everyone is saying, I should flush the engine using the fresh water attachment and have the machine tilted. After flushing, I should put it back down in the water in the vertical position for a moment and then tilt all the way up for winter storage. I presume that the fresh water remaining in the lower end will mix out with the salt water when the engine is vertical and then it will all drain out when I tilt it back up again??

 

[CJBROWN]

Thanks guys for all your helpful input. My boat is kept year round in salt water and in our parts we do go below freezing for a few months of the year. From what everyone is saying, I should flush the engine using the fresh water attachment and have the machine tilted. After flushing, I should put it back down in the water in the vertical position for a moment and then tilt all the way up for winter storage. I presume that the fresh water remaining in the lower end will mix out with the salt water when the engine is vertical and then it will all drain out when I tilt it back up again??

The lower unit doesn't drain when it's tilted up.

What do you easterners do with your motors on moored boats when it's going to freeze?

 

[JOSH S]

If you really wanted to you could make up a 5-6foot piece of hose with a male hose fitting on one end and a funnel on the other and put some pink rv anti-freeze in through the flush port. I've done that for years without a problem. CJBrown, I've been flushing this way for about 15 years and no problems yet. My understanding is that the flush port pressurizes the top side of the cooling sytem and forces stuff out through the operational inlet. Backflushing it is called. Never seen any overheating problems using this technique.

 

[Desperado]

As an added maintenance step, I flush with Salt Away using an inline adapter. It may be over kill, but it gives me piece of mind.

 

[catch22]

In the winter....

On a trailer, always leave the motor down, (verticle).

In a slip, (salt water) we also leave the motor in the down position, (submerged). Usually starting in December, (in recent years anyway) when air temps near the shore start to drop below freezing. The water temps are usually still higher than air temp, so it's safer to leave it down. Salt water starts to freeze around 28f too, I believe. So that's another safety margine.

If it got really cold over night and you forgot to leave the motor down, you should lower the motor, and wait a few minutes for the warmer salt water to thaw any water that may have froze in the lower unit. This is no garrantee, but it's a another method people use. But again, safest thig is to leave it down.

In fresh water... you better have your boat out by then. :wink:

I also do as Josh S suggests for winter storage. Short length of garden hose and a funnel, connected to the muffs. I run about 3/4's of a gallon into the muffs, after the engine has been running and warmed up. Usually after about a half a gallon, you'll see it exiting the pi$$er. I don't think it's necessary, but it sure can't hurt. Just a little extra piece of mind.

 

[vangrady]

This is interesting. My boat and engines have been kept in saltwater for the past nine years tilted up and in below freezing conditions (even the ocean gets a 1" layer of ice on the surface around my boat) for about four months of the year without any problems. I was under the impression that all of the water drains out as you tilt the machines up. If I flush with fresh water in the tilted position and then submerge the engines back into the ocean and then tilt up, would the fresh water left in the lower leg not mix with the saltwater and prevent freezing?

 

[catch22]

This is interesting. My boat and engines have been kept in saltwater for the past nine years tilted up and in below freezing conditions (even the ocean gets a 1" layer of ice on the surface around my boat) for about four months of the year without any problems. I was under the impression that all of the water drains out as you tilt the machines up. If I flush with fresh water in the tilted position and then submerge the engines back into the ocean and then tilt up, would the fresh water left in the lower leg not mix with the saltwater and prevent freezing?

As far as the "below freezing" conditions, you mention above. All I can say is, you've been lucky.

When you tilt the motor up, all the water does not drain out. The next time you have the boat on the trailer, check it out. Shut the motor off after you finish flushing, raise the motor and remove the muffs. After the water stops draining, lower it and see what happens.

One thing I forgot to mention was... in the winter, I do not flush the engine with fresh water because of the risk of freezing.

I would agree that if you lower the motor and then raise it, after submerging, the salt water would probably fill any voids in the water pump. But... if you leave the motor tilted up, rain can acccumulate in the prop hub area, freeze and cause damage. I've seen it happen.

On the other hand, if I walk around the marina, (Capemay, NJ) in the middle of Decmber, I would say half of the boats have their motors down and half are up... so?

By the way... it's August... WTF are we talking about this for? :evil: :lol:

 

[seasick]

This is interesting. My boat and engines have been kept in saltwater for the past nine years tilted up and in below freezing conditions (even the ocean gets a 1" layer of ice on the surface around my boat) for about four months of the year without any problems. I was under the impression that all of the water drains out as you tilt the machines up. If I flush with fresh water in the tilted position and then submerge the engines back into the ocean and then tilt up, would the fresh water left in the lower leg not mix with the saltwater and prevent freezing?

Om my Yami, the water will drain out of the cooling chambers when tilted up but water will remain in the prop hub and prop exaust port.
I always flush after a run and when it gets near freezing, I put the motor down while in the water.

 

[CJBROWN]

>snip
When you tilt the motor up, all the water does not drain out. The next time you have the boat on the trailer, check it out. Shut the motor off after you finish flushing, raise the motor and remove the muffs. After the water stops draining, lower it and see what happens.
>snip
By the way... it's August... WTF are we talking about this for? :evil: :lol:

This I know to be true because mine is always on the trailer. :wink:

I use the flush port. If you shut off the tap water and disconnect, let it drain, then lower the motor, a LOT of water drains out. A motor flushed tilted up in a mooring is going to have freshwater sitting in it to freeze.

If it was me, for a cold winter in the east, I would leave my motor tilted down in the salt. Paint the lower unit with anti-fouling and and let 'er sit. Better yet, pull the boat and dry-store it.

Yeah, August???? I was curious though what these poor guys do back there.

 

[JUST-IN-TIME]

you can flush while running, but you need to cover up the 2 vent holes on the drive

i might show you guys one day, but yamaha will be pissed at me because they said do not show anybody!!!

 

[catch22]

but yamaha will be pissed at me because they said do not show anybody!!!

Why's that... what's the big deal?

 

[JUST-IN-TIME]

because you can fry water pumps in 10 seconds

covering their butt's!!!

i will show where they are in the winter, after my training

still want to be good in with them, LOL