posted 01-24-2005 06:00 PM ET (US)        

I remove the plugs and spray a can into the cylinders and turn the engine over by hand to be sure the solution has saturated in, behind, and under the rings. Then I put the plugs back in (but don't tighten), tilt the engine horizontal so the solution sits on top of the pistons. I put the cowling back on and let it sit overnight.

The next day I remove the cowling and spark plugs. I use an air compressor to blow the solution out of each cylinder and turn the engine over again about 10 times by hand, not with the starter. Then I put all the plugs back in (and index the plugs--only mandatory on Bombardier's Evinrude FICHT engines and for racing engines or high-performance injected engines.).

Next I either launch the boat (recommended), or put it on the hose, and start it. Keep your hand on the key because the engine will want to over-rev and burn off the excess solution. If it over-rev's, shut her down and re-start her again. You may have to shut her down sometimes up to three times before you burn off all the solution. If the boat is in the water, just start her and put her in gear and the prop will give enough resistance so the engine won't over-rev as it would if she were in neutral.

It is very, very, very important to de-carb. Carbon build up is on top of the list of the things that destroy engines (and right next to it is over-propping). I know it sounds like a lot of work, but it really isn't. And it's absolutely essential in maintaining a healthy engine. I know, there are guys that have never done a de-carb and scoff at it, but the oils and fuel of today aren't as they were just a few years ago. They're playing with fire by thinking they are smart or cocky saying "BS--my engine doesn't need it." Only a fool would think that way, but this world is full of fools.

Do it and enjoy a nice healthy running engine.

posted 01-24-2005 06:41 PM ET (US)            

Would the same be true of four-stroke engines? I know you are mainly a two-stroke guy but is there anything we four-stroker owners should know to prevent problems in our motors?

posted 01-24-2005 07:26 PM ET (US)            

Yes, four-strokes are not immune to carbon build up and must also be done. Keep in mind, both the two-stroke and four-stroke engines are going to smoke like you can't imagine until all that carbon is burned off. It takes more than a few minutes to stop smoking.

I recommend you do it out on the water some place because when you start her back up you won't be able to see your house in all of the smoke. I'm serious. It's gonna smoke like a huge fire.

There's no need to run the hell out of the engine after the treatment, just take a nice leisurely cruise, not a wide-open blast. It is recommended to replace the plugs after the treatment because you won't believe the residue that is going to come out of your engine.

Do the treatment and come back here and tell us how the engine is now running and if there's any difference in the way she idles or runs at WOT.

posted 01-29-2005 06:52 AM ET (US)            

I have been waiting until we get some warmer weather over here to de-carbon my 90-hp 2-stroke Merc. I have a couple of cans of Quicksilver "Power Tune" that I will be using.

Is there any way of doing this without having the boat in the water? The problem is letting it sit overnight as I always trailer my boat. The instructions on the can of "Power Tune" state : "let the engine stand 15 minutes or longer". I also think that letting it stand longer would dissolve more carbon, but how long? Wouldn't letting it stand too long have an adverse effect on the carbs or injectors if the solvents have evaporated?

Would using a fuel additive like "Quickleen" increase the time intervals for de-carbonizing?

Thanks,

Erik

posted 01-29-2005 09:26 AM ET (US)            

• QuicKleen Engine Treatment--"Unique fuel tank additive for 2- and 4-cycle marine engines that combats buildup of combustion deposits, corrosion and performance-inhibiting effects caused by using poor quality fuels." This product comes in a bottle and is usually poured into the fuel tank is a recommended ratio to the gasoline.

• Fuel System Cleaner--"Maximizes fuel economy and horsepower and extends spark plug life. It does this by cleaning the carburetor, fuel system, intake valves and injectors." This product comes in a bottle and is usually poured into the fuel tank in a recommended ratio to the gasoline.

• Power Tune--"Keeps your engine running smoothly and quietly by helping remove internal carbon, varnish and gum deposits. Not for use during storage." This product comes in an aerosol spray.

Bombardier has similar products for engine care:

• Engine Tuner--"To prevent harmful carbon, gum and varnish build-up, use once every 50 hours of operation. Just spray through the carburetor intake of any 2- or 4-cycle engine." This product comes in an aerosol can.

• 2+4® Fuel Conditioner--Routinely added to the fuel tank in a recommended ratio to the gasoline.

Yamaha also has:

• Ring Free--"Special formula removes deposits that cause ring stick and wear. Cleans carbon and varnish from rings, pistons, combustion chamber, intake and exhaust manifolds, and carburetor. Aids in improving power and efficiency while extending engine life." This product comes in a bottle and is added to the fuel tank in a recommended ratio to the gasoline.

posted 01-31-2005 07:08 PM ET (US)            

Would you recommend this procedure on a Mercury Optimax (1998 135hp), as well? I've used Chevron and Quikleen on it regularly, and the motor runs great. This may be a dumb question given that the Ficht is also direct injection, but I'm a bit paranoid about doing anything to my motor (the experience of blowing a powerhead will do that to you).

posted 01-31-2005 09:00 PM ET (US)            

Looks like I'll be decarbonizing my optimax in the near future . . .

posted 05-07-2005 09:28 AM ET (US)         

I just got the surprise of my life this morning when talking with the mechanic at my dealership...he says under no circumstances should I use Power Tune (or any similar spray product) on my Merc 115efi as it can dry out the lubrication in my efi system and cause serious damage to the engine.

I am no stranger to this product and have used it several times on smaller 2-stroke outboards with excellent results. I challenged him to prove to me why any current technology outboard (EFI, carb, DFI) cannot use this product. He re-stated these products are fine for carbs and DFI but no good for EFI. I asked him how I was supposed to deal with carbon on my engine and he said only use the Merc Quickleen fuel additive - not any type of spray.

posted 07-06-2006 05:46 PM ET (US)            

I'm sure he'll either e-mail you or comment publicly, but Backlash reported this past weekend that he had followed your procedure to a "T" this spring, and running the boat out of Leland Michigan to the Manitou Islands (a 50-some mile round trip in cold lake Michigan waters), reported that the engine ran better than ever.

What works for Steve works for me - I'm going to do this to my 6 HP Johnson (my E-Tecs shouldn't need it for awhile!) this weekend.

Dave

posted 07-07-2006 08:00 AM ET (US)            

http://continuouswave.com/ubb/Forum4/HTML/004251.html

posted 07-07-2006 11:19 AM ET (US)            

Late last summer my 1992 200HP Yamaha 2-stroke was starting to idle rough and would hesitate and stumble somewhat when accelerating. I thought the carbs might need rebuilt (they have never been rebuilt), but decided to try your Sea Foam treatment first. About five years ago I ran Yamaha Ring Free (in 40 gals. of gas) thru the engine and noticed no excessive smoking or any change to the engine performance at all.

I bought a can of Sea Foam and a can of Deep Creep. I removed the air intake for the carbs and sprayed the Deep Creep into the carbs at about a 800 RPM idle on the hose. I was surprised I couldn't get the engine to stall out. I emptied almost the entire can into the carbs and shut off the engine. The engine smoked excessively during this procedure.

Next, I replaced the carb air intake and removed the spark plugs. I sprayed the remainder of the Deep Creep into each cylinder as I rotated the flywheel by hand. I then tilted the engine into the horizontal position and poured about a 1/3 of a cup of Sea Foam into each cylinder and rotated the flywheel about ten times. Next, I reinstlled the spark plugs and left the engine tilted over night.

The next morning I tilted the engine to the horizontal position and fired her up. I set the idle around 900 RPM and was surprised that the engine did not race, but did run rough for several minutes and smoked like the devil. I let it run at idle for 10 minutes on the hose and by then most of the smoking had subsided.

Last weekend, on our trip to Michigan, was the first time I had it in the water since the Sea Foam treatment. It started normally and smoked more than usual. On our run out to the Sleeping Bear Dunes with Dave in "Gambler" I had a chance to really open it up. After this 10 mile run most of the smoking had stopped and the idle and acceleration were smoother than it had been for a long time. My wife even thought the engine seen quieter!

In conclusion I think the Sea Foam/Deep Creep combo certainly cleaned out any carbon/build up present in the engine and carbs. I had brought along a fresh set of plugs (thinking the plugs would need changing), but the Sea Foam apparently cleaned them as well! I did not notice a great deal of crud present in the exhaust hub after this procedure and honestly think the engine did not have a great deal of carbon build up. I would definitely recommend this treatment to anyone and will repeat every couple of years.

Thanks, Sal!

Steve

posted 07-08-2006 12:04 AM ET (US)            

However, when I tilted my engines after pouring the seafoam into the cylinders, the seafoam was dripping pretty heavily out of the carbs and into my splash well and making a big mess. I had to tilt the engines back down a little bit. Is this normal??

posted 01-18-2007 09:41 AM ET (US)            

My problem: I have an early 80's Mariner 3.5 long shaft that I have used as trolling motor on 1968 Sakonnet and kicker on my 1980 ictoria 18 sailboat. It had not been used for about 3 years until I tried it last summer on my Sakonnet. After abut 20 mins or so of exhaustive rope pulling I finally got it to start and run pretty good at idle. However, as soon as I'd try to speed up a little at idle or in-gear (while tied to dock), it would immediately stall. Would continue to start Ok but still stalled out. Gave up and put Mariner back in garage. Son-in-law thinks he can do carb rebuild this spring but wondering if I should try your decarb procedure first before attempting carb rebuild Thoughts and recommendations please for my Mariner.

posted 01-18-2007 10:31 AM ET (US)            

I think a carb rebuild is certainly in order with the symptoms you describe.

However, a healthy dose of Sea Foam will certainly clean it out. It cannot hurt, only help.

posted 04-04-2008 12:06 AM ET (US)            

So I gave the chambers another hit of spray and left em for 15 mins. This time I started it all up a little quicker and was getting the smoke I thiought I should be getting. Still not a lot and still no where near looking like your house is on fire. I ran the engine until most of it had burnt off. Pulled the plugs and this time a few bits of crud on the plugs... How does that work? I leave it for 15 mins and get cruds, leave overnight and get nothing? Should I assume that the overnight treatment liquified most of the crap, and because most of the engine tuner seemed to run out the leg when I lowerred it, that is why I didnt get much smoke the first time?

Also, how "bright" should the piston heads look? Shining a torch down em, they sstill seemed to have some deposits on them that look rather hard.