Decarb

[JakeCo88]

I did a decarb today following the instructions in the top secret file:

Brought the engine up to temp, pulled plugs, put a shot of seafoam in each cylinder, let set for about 15 minutes. Mixed 3/4 can of seafoam with one gallon of premixed gas, ran the gas through the motor spraying in the remaining seafoam. It smoked like crazy and the water looked like sludge. After I ran the full gallon, it didn't want to restart. I put in some old (but still good) plugs and it fired right up. My concern is, it still smoked really bad when running regular gas (premixed, no seafoam).

Is this normal?
Do I need to do anything else? Judging from the gunk on the spark plugs I pulled, there must still be some gunk inside the rest of the motor.

Below is a video of it running with the seafoam, it smoked equally as much on regular premix. I only ran it for a couple of minutes, maybe I just need to let it run a while?

 

[Patate]

Re: Decarb

I think you need to run full throttle on the lake for at least 5 minutes, and replace the plugs after

 

[Will Bark]

Re: Decarb

I decarbed my 150 on the muffs and cleaned out the mosquitos for about 4 blocks around the house. Agree with carry it to the lake and run WOT until the smoking stops and then change plugs. Motor runs the best it has in years.

 

[Georgesalmon]

Re: Decarb

Do the above. It will take forever to clean it up at idle/ Need to WOT that thing at the lake.

 

[JakeCo88]

Re: Decarb

Thank you gentlemen. I'll give that a shot. Follow up question: Is it necessary to do that soon? I'm in the middle of law school finals and probably won't be able to make to the lake until next week.

 

[AlTn]

Re: Decarb

shouldn't make much difference..you can do the whole procedure again then run it wot on the lake if you want to

 

[archcycle]

Re: Decarb

The reason for idle is to hose the cylinders down with the very heavy mixture of seafoam and then shut it down and let it soak. It soaks into the deposits, then you run it again and hose it down with the heavy mixture for another few minutes.

The idea is that you're spending more time with seafoam in contact with hard caked on carbon deposits. If running it hard was a good way to get rid of those really caked on deposits that build up slowly over long periods then you wouldn't have them to begin with.

If you're not going to let the concentrated fuel/seafoam mixture soak then you might as well just follow the directions on the can and run it through in normal usage at 1 oz to 1 gallon considering that the whole concept behind the 16oz to 1 gallon is that you're going to let it soak in.

If your plugs are dirty then you need to run some more cleaner through it. The seafoam should leave your plugs clean once there is no more filth to clean out of the cylinder. Or just clean the plugs. They're just dirty, they're not broken.

 

[kfa4303]

Re: Decarb

+1. These old motors smoke quite a bit in the test tank under the best circumstances, but they will smoke out the neighborhood when you do a decarb. You will want/need to run the motor at WOT as soon as you get a chance. That will allow the motor to get up to temp and burn off the last of the old goo. You should notice a smoother idle and better overall performance once the decarb procedure is complete.
Good luck on finals...even if you are gonna be a lawyer

 

[Sea Rider]

Re: Decarb

Don't know if Sea Foam performs same as Power Tuner, with PT, start engine let warm, remove carb air silencer if happens to have one, throtltle to fast idle while squirting power tuner through carb throat, engine will begin to miss, repeat several times, throttle a bit more and squirt PT untill engine dies, let PT soak in for at least 1/2 hour, with old plugs and inmediately after, go for a wot spin for some minutes to burn all PT remains. Place new and well gapped plugs, and that's it folks!! Should decarb with PT every 100 worked hours to keep pistons, rings and cylinder head in mint top clean conditions and running as a champ.

Happy Boating