Seafoam?

[CDEAN1469]

i have an 88 25 horse johnson that im pretty sure hasnt ever been treated w/seafoam my question is lets say i have about 3 gallons of fuel left in my tank would it be a good or bad idea to add seafoam to it and run the boat like normal or would the boat run bad

 

[iwombat]

Re: Seafoam?

With three gallons, add two cans of seafoam and it should do the trick. It's going to smoke a lot though. You'll also want to stop and start the motor a few times with a 15 minute (or more) period of downtime.

 

[CDEAN1469]

Re: Seafoam?

so less fuel would be better so will it smoke the whole time or will it go away

 

[iwombat]

Re: Seafoam?

It'll smoke while it's burning out all the carbon. It'll smoke a bit more than normal with just the seafoam but not gobs. The soak time is so the seafoam has a chance to work through the carbon deposits. Run 15, stop 15, run 15, stop 15 until the smoke clears out is generally how I do it. There's a more precise write-up in the FAQ.

 

[crxess]

Re: Seafoam?

A+ for Seafoam.

I fed about 6 ounces through the carb on my 6hp last week. Added the rest to the 2 Gal I have left in the tank.
Motor smoked like an old train while feeding. Running on tank isn't a problem.
Just pulled the head today to replace due to Heli-coil issues.
Before, on inspection, head was coated in carbon. Now I hate loosing it. Inside is spotless - like new.

 

[tashasdaddy]

Re: Seafoam?

Decarb, take a can of seafoam put 3/4 of it in the gas tank, with only 1 gallon of premixed gas. put the rest in a spray bottle. start the engine, and let it come up to temperature. then remove plugs, and them some real good shot of seafoam into the cylinders, replace plugs, let sit 15 minutes. restart, and spray the rest of the seafoam into the carbs, so the the motor almost stalls, wait and repeat until the seafoam is gone.then take for a wide open spin. then put in new plugs, ad premixed gas to the tank, and take it for a wide open throttle spin. it is going to smoke like a house on fire, during this process.

 

[CDEAN1469]

Re: Seafoam?

is it better to do this in the water going down the lake on the trailer at the ramp or in my yard with the muffs on it and what speed idle or full throttle

 

[MarshMan73]

Re: Seafoam?

After doing this procedure my self today. I would definetly would npot do it near anybody, especially a boat ramp. I thought I was going to have my neighbors come over and complain. Thing smoked like.. well.. a freight train or a house on fire hit by the freight train, was my case today. I peeked in the plug hole today and there was a ring of goo around the very bottom of the plug threads and the pistons were thick black. After doing this it is now gone and I can see the piston now, but is still darkly colored Plugs are shiny but very wet. Inside prop is black and nasty and so is the water that came out of it. Figure I need to do it again before I go run it, so I'm letting it soak some more overnight. Stuff really does work, mixed at 1 can per gallon of gas, so be prepared to rid the neighborhood of mosquitos as well as your carbon.
After the mess I made in my drive today, I'm sure I'll get a letter from Al Gore or Obama wanting me to pay for some carbon credits!

 

[halas]

Re: Seafoam?

Decarb, take a can of seafoam put 3/4 of it in the gas tank, with only 1 gallon of premixed gas. put the rest in a spray bottle. start the engine, and let it come up to temperature. then remove plugs, and them some real good shot of seafoam into the cylinders, replace plugs, let sit 15 minutes. restart, and spray the rest of the seafoam into the carbs, so the the motor almost stalls, wait and repeat until the seafoam is gone.then take for a wide open spin. then put in new plugs, ad premixed gas to the tank, and take it for a wide open throttle spin. it is going to smoke like a house on fire, during this process.

Are the new plugs important? Will they be damaged by the decarbing?

 

[gatorhead]

Re: Seafoam?

Replacing the plugs is not absolutely necessary. I would suggest to run it as described thus far and then to remove the fuel lines from the motor and let the motor burn all the fuel off. Remove the plugs blow them out with the compressor and put em back in.

I also use seafoam in my vehicles. You take a can and open it up and take the vacuum line off your brake booster while its running and let it suck up about 1/2 of the can into the manifold until it either stalls or starts to, then cut motor off let it sit 15 mins and then start it back up. add the remaining seafoam to your tank. It will also smoke the same way but it will definitely free up hp and improve your gas mileage. You can also add it to your oild about 500 miles before an oil change and then run it as normal. It will decarbon the bottom end and clear up and oil galleys and passages. You only want to do this within that 500 miles of an oil change. It works very well and I use it often to flush all sorts of engines

 

[iwombat]

Re: Seafoam?

As an oil additive it does wonders for hydraulic lifters too.

 

[Randyg123]

Re: Seafoam?

I waited for a windy day and took mine to the river. Tied off downwind from everyone and performed the procedure as described in the FAQs (and TD described above). I was expecting more smoke than what I got but it did smoke quite a bit. I think more of a campfire with wet wood than a house on fire. The spray bottle I was using wasn't misting well so I could not spray enough to get her to approach stall, but then again my idle is set too high anyways so that may have created that situation.

I did not replace the plugs right afterwards (forgot to bring 'em) but when I got home, I inspected them and they looked pretty good (lightly wet, relatively clean, tan ceramic). I wasn't going to change them but it is recommended by the experts so I did last night.

 

[iwombat]

Re: Seafoam?

The smoke is from burning off the carbon. The more carbon the more smoke. When I treat mine in the spring they don't smoke much anymore.

 

[MarshMan73]

Re: Seafoam?

Probably by having the motor in the water instead of hanging in the air on muffs diffuses the smoke some. Also you said you were misting it in? That is effective, but not as effective as running it 1 can per 1 gallon of gas right in the fuel line. Misting brings back memories of an old timer that used to use a spray bottle with water, yep water, and would spray it into the intake of a running warm car engine. Said the water would steam clean the cylinders. Then he would follow it with a little transmission fluid. Boy that was some smoke!

 

[tommy.noble]

Re: Seafoam?

I had some power issues with my 100 johnson...ended up disconnecting the fuel line from the gas tank and just stuck the fuel line directly into the seamfoam bottle and used my fuel ball to draw just straight sea foam into the system. Smoked like crazy...took it out the next morning and it jumped right out of the water....GREAT STUFF!

 

[CDEAN1469]

Re: Seafoam?

I started the seafoam treatment yesterday in my back yard with my motor in a barrel so i cant run the engine wot because it throws all of the water out of the barrel also i wasnt able to finish the whole gallon of gas last night because i have neighbors and i dont want them mad because there neighbor is outside with a boat motor running will it hurt anything that i didnt finish it all i plan to finish it today and will it hurt that i couldnt run it wide open

 

[pcrussell50]

Re: Seafoam?

I had some power issues with my 100 johnson...ended up disconnecting the fuel line from the gas tank and just stuck the fuel line directly into the seamfoam bottle and used my fuel ball to draw just straight sea foam into the system. Smoked like crazy...took it out the next morning and it jumped right out of the water....GREAT STUFF!

interesting idea in your post. makes me wonder... we have the following going on:

1] carbon on the piston tops increases compression ratio, which ought to increase power, [as long as it doesn't detonate]

BUT

2] carbon blocking the various ports in a 2-stroke ought to reduce power

sooo... i wonder what the net is?

-peter

 

[wilde1j]

Re: Seafoam?

Carbon is bad, period! It causes stuck rings, overheating and a number of other bad things. Not possible to make a case for carbon being good.

 

[pcrussell50]

Re: Seafoam?

Carbon is bad, period! It causes stuck rings, overheating and a number of other bad things. Not possible to make a case for carbon being good.

not debating that at all, actually. i was just making theoretical considerations about whether carbon buildup causes a net loss of power, whereby removing carbon restores power? or not so much?

-peter

 

[Daviet]

Re: Seafoam?

Because the fuel mixture travels across the piston, a carbon build up can disrupt the air flow. I admit that it might not disrupt it very much but it could cause a problem.