Should I pour water in the intake to clean carbon deposits?

[System_Error_117]

Hey Gang,

Has anyone had much luck with some of the old carbon cleaning tricks on our engines? I ran some seafoam spray through mine one time that seemed to smoke up the entire lake, lol. So I can assume I had a lot of carbon build up.

Has anyone had luck doing the old water in the intake method for de carboning their valves and cylinders?

I could set a drip up and let it run for a half hour or more and really get it squeaky clean!

[ndutton]

I ran some seafoam spray through mine one time that seemed to smoke up the entire lake. So I can assume I had a lot of carbon build up.

Not so sure you can reach that conclusion by putting a petroleum solution into the intake, suspect the same would happen on a brand new engine. Are there any other indicators of carbon build up? Have you inspected the cylinders with a borescope?

I acquired a tired A4 several years ago, it ran but poorly. I rebuilt it as a spare and found no carbon build up whatsoever.

[System_Error_117]

Sticky Valves

I haven't had any issues on my engine. But it seems a lot of boats in our club are having issues with sticking valves recently. Just don't want to become another statistic.

I'm pretty good with all other maintenance. Oil filter kit installed. Acid flush the block every few years. But it is an original untouched engine internally.

I've seen the water vapor trick do wonders on older European car engines with early direct injection systems that dirtied valves like crazy. Just thought it would be good insurance for the longevity of the motor.

[ndutton]

Sticky valves around here are usually from water incursion into the combustion chamber.

[Al Schober]

I'd vote no on the water injection. My big concern is what it's going to do to the pistons. I've seen pistons with hunks of aluminum missing and with broken rings that I suspect was due to water in the combustion chamber. I'd rather see you add a little MMO to the fuel.

[joe_db]

Short answer is no, water in there is why the rings get stuck in the first place
There are solvent/cleaner/lubricant type chemicals for this task. My first step is MMO and see how that works.

[edwardc]

+1 on MMO. I regularly use it in the oil, and occasionally in the fuel if I’m having sticky valve issues.

[System_Error_117]

Interesting! It seems its more of an automotive fad perhaps using water vapor to clear deposits off of the combustion chamber.

I know a key for it to work properly is proper atomization of the water, where its completely vaporized by the time its sucked into the cylinder. The engine also needs to be fully warmed up to boil the water as its pumped through the system and really burn off any carbon.

Our carbs do a great job of keeping our intake valves clean soaking them with fuel and other additives we might add to the fuel. Wasn't sure if there would be any cleaning happening on the exhaust side being already burnt additives.

Sounds like no one has really had much of an issue with caked on carbon, so it might not be worth pursuing!

[joe_db]

The issue with modern cars is they now commonly use direct high pressure injection like a diesel, so no fuel goes by the intake valves. You can put 10 gallons of additive in the tank and still not clean the valves.

[ndutton]

It's your boat so therefore your choice but without a definitive reason for doing it I propose the risks outweigh any assumed benefit. Such risks include fouling the carburetor (virtually guaranteed), rusting the valve stems in their guides and if enough water is in the cylinder* it risks a non-compressible hydraulic situation that can bend the crankshaft. Remember, unlike every other engine in the world it seems, our engine has no center main bearing so the possibility of crankshaft damage is ramped up considerably. We have 4 connecting rod journals supported only at the ends of the crankshaft.

I keep going back to this in your post #3:

I haven't had any issues on my engine

so what are you trying to fix? This is sounding more and more like phrase we occasionally use around here, "a solution in search of a problem."

*reference the title of this thread, "Should I pour water in the intake . . . ." You backed off of it later suggesting a half hour of dripping but still the risks remain for an old shade tree method that may be of zero benefit.

Sounds like no one has really had much of an issue with caked on carbon, so it might not be worth pursuing!

Yep, that's the point.