Flushing Engines

[fairpilot]

Just wanted to post about Flushing engines and salt water. My boat is a 2006 Sx230 with about 580 hrs. I am religious about Flushing at least 10 min on the hose each side. I have had manifolds off boat twice, once for a major leak and this time for a minor water leak. Both times all the cooling jackets are damaged near clogged with dried salt and crud. I also open up thermostat housings twice a year to clean because they too are full of crusty material and a jelly like substance from salt water I guess. If you are a full time salt guy better keep eye on this. I am assuming that there is not enough pressure on home water hose to provide enough pressure to blow all this out.

 

[adrianp89]

Do you use salt away or dish soap?

 

[Beachbummer]

A good portion of the flush water drains right at the water inlet, where the water normally would enter from during normal operation.

I would suggest using a tow valve when flushing. It blocks the pump which forces the cooling water to traverse the engine.

I cannot guarantee it will help, but it would be an interesting experiment for you since your already experience issues in this area.

Thanks for the heads up.

 

[Scottintexas]

Bummer has a good point, do you use tow/flush valve to increase pressure?

 

[WREKS]

@fairpilot I do not like opening up this "can of 'microbes,'" but I do not think salt is the problem. That 'jelly like substance' that you refer to is much more likely a microbial build up. The water treatment industry calls it 'biofouling.' It is the same stuff that builds up in air conditioning condensate lines that do not drain properly. A wet environment is the perfect climate. Our engine cooling systems provide the perfect climate. I have some pictures and thoughts in my signature under 'Overheat Prevention.'

 

[1WetBoat]

I know for all of us this isn't feasible but for my previous wave runners I had access to a fresh water canal real close to my house and after riding in the ocean I would drop it off in the canal and take a few high speed runs. Then when I got her home I would flush on the hose also. Never had an overheat problem with that technique. Had the head off(2-stroke) a few times for various reasons and never noticed any considerable build up.

With the boat its different obviously, but for the times I have gone out to the ocean I also try to run it on the local river here and while its mostly brackish water(Alafia) i feel its better than pure salt water. Then I flush it on the hose at home with the full pressure of the hose till the salt away container is clear which is roughly around 10 mins or so.

I am going to look into the tow valves also because I can see a ton of the saltaway back flushing out the pump through the strainer. I don't know if everyone's else is like this but on my AR the rear hatch where the tow valves would ideally go is majorly cramped and reaching in thru the access hatch is prohibitive.

 

[Brad_Ct]

I feel your pain, this came off our boat that obviously was not properly maintained before we bought it.

 

[kgower]

@WREKS would hard water deposits cause similar issues?

 

[WREKS]

@kgower Going back to @fairpilot 's 1st post, the 'crusty material and a jelly like substance' develops after flushing, when the engines just sit with whatever residual water remains in their cooling systems. It is a microbial buildup. This is not a salt problem. The same substance builds up on both sides of the head gasket and especially in the cylinder water jackets. Because the head gasket only has small holes, the flow of water through it is impeded. It cannot be flushed out. Keeping the engine and oil cooling systems internally dry, when not in use, is one way to prevent microbial buildup.

 

[Cobra Jet Steering LLC]

I have 870 hours in salt water I use a pig tail with car wash soap , the type that has the wax in it never had any issues with the cooling system and you can see the soap coming out the pump and pisser tube so you know when it is finished flushing , to each their own but I have a saying if it works keep doing it but I also add zinc to my pumps and ride plates.

 

[14SX190]

x2 to adding dish soap into flush line.
Or the salt away, but top one is under my sink

 

[fairpilot]

Do you use salt away or dish soap?

No, use to use salt a way but swear it ruined manifolds after prolonged use. Just replaced both sides so may try dishsoap now

 

[fairpilot]

Bummer has a good point, do you use tow/flush valve to increase pressure?

I do not

 

[fairpilot]

Bummer has a good point, do you use tow/flush valve to increase pressure?

I do nohi

@kgower Going back to @fairpilot 's 1st post, the 'crusty material and a jelly like substance' develops after flushing, when the engines just sit with whatever residual water remains in their cooling systems. It is a microbial buildup. This is not a salt problem. The same substance builds up on both sides of the head gasket and especially in the cylinder water jackets. Because the head gasket only has small holes, the flow of water through it is impeded. It cannot be flushed out. Keeping the engine and oil cooling systems internally dry, when not in use, is one way to prevent microbial buildup.

How do you keep inside cooling system dry?

 

[WREKS]

@fairpilot I have been running engines for 60 flashes In No-Wake mode, without supplying water. I have not had any overheat warnings while doing this and the engines get warmed up, hopefully drying out cooling system.
Like you, I always flushed for up to ten minutes after being on the water and still had overheating.
Last March after pulling both engines and cleaning the cylinder water jackets and oil cooler water jackets, I went on the water to test. No overheating. I flushed the engines as always and thought the overheating problem was resolved. But, afterward, while having the boat layed up, I periodically started engines and ran on hose for up to ten minutes each. That is where the problems began. I started getting overheating on engines that had only been in the water for a few a hours. I pulled both engines, again and found the cylinder water jackets and oil cooler water jackets packed with that jelly like substance you mentioned. Now, I am preparing to water test again.
Regarding tie valves: I do not think pressuring the cooling system to attempt better flushing is wise. There is barely a quarter inch space between water passage ways and cylinders. Water/steam could be forced into cylinders.

 

[Beachbummer]

The pressure created by the pump at high rpm is certainly higher than the pressure and volume the hose can provide. Closing the tow valve does not increase the pressure beyond that already normally experienced by the pump at higher rpm.

Look at the stream from the pissers at speed. Much more powerful that what you get on the house with the tow valve closed.

You are not adding water beyond what normally flows, but closing the deficit a little bit.

 

[Cobra Jet Steering LLC]

I have seen water jackets that were full of sand when driving in no wake zones in traffic with sand bars or shallow water look at the color of the water especially when a large boat is ahead of you, if you see it is the color of the sand you are sucking jn sand with the water, years ago I noticed that traveling in johns pass so I would wait for the large boats to get ahead of me before I went in The last 2 engines I had were in the high 800 hours never had any issues with corrosion or overheating I have said this many times and it is how I flush my engines and I run in the Gulf of Mexico, I use car wash soap in a pigtail when I flush the engines when I see that the soap has stopped making suds exit the engine I shut off the water and let the engine run about 30 seconds. I used dish soap for many years prior to the car wash soap however I like the fact that the car wash soap leaves a thin film of wax coating the water jackets. The other thing I do not do is hit the throttles on the trailer to remove the water from the mufflers. I just let it idle for a short time to push out excess water from the muffler, Revving a 4 stroke engine with all those valves and chains is bad for the engine, that procedure was for 2 stroke engines very few moving parts no valves and no timing chains.

 

[WREKS]

@Beachbummer The pressure created by the pump for thrust is not the pressure of the cooling system. The pressure drops immediately and continuously as it goes through the hoses and passageways. Then the cylinder head gasket creates an enormous block to flushing because of its small holes compared to the cavernous water jackets in the cylinder head and cylinder block that it divides. The jelly like substance that Fairpilot and others have observed defies removal by high water pressure.

 

[Beachbummer]

Without disagreeing with anything you said in your last post, I was addressing this statement from you:
--
Regarding tie valves: I do not think pressuring the cooling system to attempt better flushing is wise. There is barely a quarter inch space between water passage ways and cylinders. Water/steam could be forced into cylinders.
--

I do think if the issue is left over salt water, additional water pressure and volume(perhaps along with a little dish soap) could help prevent the issue.

 

[WREKS]

@Beachbummer It might. If the oil gets milky, I would refrain. on the dish soap.