Confused with decarb instructions

[wlbolerdo]

In TD's directions on decarbing a motor, it says to add 3/4 of seafoam into the fuel tank with 1 gallon of pre-mixed fuel. Is the tank suppose to be empty other than this 1 gallon? I have an 18 gallon fuel tank in the hull!
Also, can I do the seafoam in the cylinders today and take the boat out tomorrow for it's WOT run?
Last question, which is best for this procedure, ear muffs or a test tank?
Wayne

 

[iwombat]

Re: Confused with decarb instructions

Most people use a little 3-gal portable tank for the decarb. And yes it's assuming your tank is otherwise empty.

You can do the spray procedure anytime w/ no issues running it later.

I generally do my decarbs on the muffs, but it's better to do it on the water.

 

[wlbolerdo]

Re: Confused with decarb instructions

Thanks for the reply.
Would a test tank be similar to being on the water during the spray portion of the decarb? I guess I don't want to blow anything out the exhaust and suck it right back in, if this is possible? I hope I don't sound paranoid.
Wayne

 

[ezeke]

Re: Confused with decarb instructions

When you do a full annual de-carbon treatment you may need to do as many as three treatments to get all of the carbon out of the firing chambers, rings and exhaust ports, so its easier to have a small separate tank of premixed gas and oil, add the SeaFoam and run the motor for the prescribed period, then spray some straight SeaFoam directly into the chambers through the spark plug holes.

When Captain Dunkleberger started advising on this treatment, he was fairly specific about the time needed to break down the carbon, but when you can see the tops of the pistons no longer have any carbon caked on them, you are about finished.

You might find that reading through his treatment advice will add a little to what has already been said: http://forums.iboats.com/showthread.php?t=158076

BTW, when you do a decarb running in a tank, everything that goes through and is removed from the engine winds up in the water and is circulated into the cooling system. I would highly recommend a different plan whenever possible.

 

[wlbolerdo]

Re: Confused with decarb instructions

Thanks to both EZEKE and IWOMBAT for their help and replies. I'll skip the tank and go with muffs or open water! Thanks again guys.
Wayne

 

[asdasc]

Re: Confused with decarb instructions

After reading all this, I have a couple questions. It sounds like running the engine overloaded so that max RPM is too low is really bad for the engine.
I have an 18HP 1959 Johnson that is mounted to a very heavy 16' pontoon boat. I got the whole thing all set up, fresh carb rebuild, etc and tuned the carb per the FAQ from Dan Reeves. I was pretty pleased with the performance, but it sure doesn't rev anywhere near what I would guess is the reccomended 4500RPM.

1. Is there anyway to measure the RPM on these older motors with magnetos?

2. How bad for my motor is this set up? Do I NEED to find another prop with lower pitch?

Thanks!

 

[tashasdaddy]

Re: Confused with decarb instructions

change prop definitely. you are lugging that motor terribly.

 

[coolguy147]

Re: Confused with decarb instructions

lol i got a 10hp on a 20 foot pontoon 8 foot wide

the motor is 1959 evinrude sportwin 10hp i read somewhere that 4500 is like recommened speed or something in some booklet like 5 pages of diagram of parts i have. give specs is what i mean

 

[tashasdaddy]

Re: Confused with decarb instructions

yes, those motors like to run at 4500-4800 at wide open throttle. if you are not getting that, you are lugging the motor, causing excessive wear. once you get the wot rpms set, the motor will be fine at all other speeds.

 

[asdasc]

Re: Confused with decarb instructions

Thanks Tashasdaddy. Can I hook up a tach somehow? I would assume I can get a cheap automotive tach and hook it to the magneto wire? I figure if is for a 4 cyl car, I would have to either halve or double the reading on the tach when used on a 2 cyl, right?