Dunk's Decarb Procedure. . .sticky??

Classic Parker Boat Forum

Help Support Classic Parker Boat Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Shannonigans

Well-known member
Joined
Jun 13, 2012
Messages
129
Reaction score
0
Location
Waterford, CT
. . ... .seems that many of you here use Seafoam in one way or another to decarb your motors. ....most recommend Dunk's method. I will be trying this for the first time this week. If all goes well I will keep up with it every 50 - 60 hours as recommended or as needed. I did a search on here for this procedure. . ...found a bunch of links to it (some don't work anymore). ... ..so I will post it below in this post and was hoping it may be made into a sticky. It seems to come up often enough. . ..It's a pretty good read. Thanks to those that recommended it. . . . ....



Dunk's Decarb Procedure

This works for Carbed, EFI, Ficht, HPDI, Optimax and even 4 strokes...First you need a separate small fuel tank. One of those 3 gal red Tempos works great or an empty gal milk jug will also work, but might be a bit messier..

I use Seafoam over the OEM stuff like OMC Engine Tuner or Merc Power Tune because in the last few years they changed the formula and you have to let them sit up 12 hours. Who's got time for that?? Seafoam you can buy from NAPA, CarQuest or other auto stores. Seafoam works in 15 mins.

You'll need 3/4 gal of gasoline and one 16oz can of seafoam for each engine. Don't forget to add 3oz of oil if you are premixing in a carbed engine. Use about 3 ft piece of fuel hose off the little tank. You connect this tank to your engine by pulling off the main tank fuel hose off the intake side of your water separating fuel filter and plug the hose off the small tank on to that fitting. Or you can separate the fuel line on the tank side primer ball, so you can still use your primer. If you have an engine that has fuel plug then you need a fuel plug on the little tanks hose.

Start the engine, let it warm up and start pulling the mix into the engine. You may have to increase the idle to keep it running once she get loaded with the Seafoam. Run the engine 15 mins in the dock or just cruising around under 2500. Then shut it down and let it sit for 15 mins. Restart the engine, the smoke you see is the carbon burning off. Do the whole thing again and let her sit again for 15 mins. If she smokes after the second time do it again, but I've never seen one still smoke after three doses. The gallon mix should be enough to do this 3 times. You don't need any wide open throttle, you don't need to change the plugs. If it's cleaning the combustion chambers it's also cleaning the plugs, but every 50-60hrs is good time to change plugs in most engines.

I cleaned a antique evinrude one time that had a 1/4" of solid carbon on the exhaust chamber walls by running a 1/2 gal of the mix through it. Seafoam has been around since the 30's and it's what they used when they were burning straight 4 stroke 40SAE oils in outboards.

You guys with the 4 strokes think you are immune from this? Those engines work 10 times as hard as any auto engine ever will and they will carbon up. I bought a Bronco two years ago that had 95,000 miles on it. When I used seafoam on it I had the neighbors hanging out of their front doors looking for where the fire was after I started it the first time there so much smoke.

Too many are under the assumption that it's totally the 2 stroke oil that causes the carbon, Wrong... it's also the additives they put in the fuels today. The carbon inhibitors in 2 stroke oil are there for this reason also. Remember when gasoline used to smell like gasoline, today it smells more like bad cologne.

For those guys that like to do the carbon treatment by spraying it down the carbs Seafoam also comes in spray can called Deep Creep. It's the same stuff under pressure. Says right on the can Oxygen Sensor Safe, for you Yam guys.

After that if your engine maunf recommends a daily additive treatment then do that in the mean time, but all 2 stroke outboard need decarboned every 50-60hrs. If I owned a 4 stroke I would do it the same. Once you are set up with the tank and hose the Seafoam is only 5-6 bucks can. It's to easy not to do it.
 
I made this post into a 'sticky' that will stay at the top of the OB forum, so thanks for that!

Besides using it on OB motors, I have literally "resurrected from death" a lawnmower, chain saw, and as pressure washer. Each was alleged to be dead and I got them for FREE .. and all were fixed using Seafoam.

In those motors (stale gas left for months/years??) I drained all fuel and added the straight Seafoam and pulled the starter through, with the plug wire removed. I let them sit for a day or two. The washer I had to do twice. All were then drained and filled with fresh fuel, then started, tuned up, and all was well!

Note, if your carbs are running OK and you only intend to decarb the cylinders, you could save some time/trouble and use their aerosol version, called "Deep Creep", and spray good long blasts from carb to carb, using 1/4 can, then do the 25-minute wait. Repeat, repeat if needed ... leaves you some on hand if/when needed to boot!
 
. . .. ..Thanks Dale!

. ....my motor just started to run a little rough at idle. I have put roughly 75 hours on it since I bought it, so it's time. .. .... I also plan on doing this procedure on my 30 HP skiff motor.. . ..which runs horrible! She doesn't get used much at all until fall, so there's a lot of time for things to gunk up. . . .even with the proper storage efforts. Fingers are crossed. . ...
 
... while Seafoam/Deep Creep is awesome ... but it doesn't replace carb tuning, just so you know.

Make note where the carb needel valve(s) are and with motor warm and IN the water (never tune an OB on muffs!), turn in (or out) 1/4-turn and let her stabilize, repeat until you achieve the highest RPMs at that lowest throttle setting.

Typically this is by turning in, then backing off that last 1/4-turn or she'll sometimes lean stall. Take motor for test run, put her up to plane fast and then back to idle. If she stumbles, but recovers, you need to fine tune it.

If when tuning an OB with 2 or more carbs, ALL must be tuned, even if you only adjusted one ...
 
Dale -i just did that to my HPDI --Wow -what a diff. it made. Your the man !!!!!
Thanks Marty D.
 
Marty D":2hh231uu said:
Dale -i just did that to my HPDI --Wow -what a diff. it made. Your the man !!!!!
For the record, I do it to my gas weed whacker, snowblower, leaf blower, lawn mower and chain saw too! Anytime I take possession of a motor I didn't buy new, or when acting up.

In fact, 3 of them were GIVEN to me when their owners bought new ones, instead of fooling w/ them. A good carb clean (immersed in carb clean can) and a Seafoam treatment and they all started right up :) !
 
. . . .not sure if they carry it. I know Benny's, Walfart, or any autoparts store. . ....



 

Attachments

  • seafoam.jpg
    seafoam.jpg
    18.1 KB · Views: 1,002
Only need a gallon's worth of mix, use a typical 3 or 6-gal OB tank ... making sure to ADD TC-W3 oil if the OB needs it ;) .
 
Sea foam works !!! I was using stabi until last year when my 250 4 stroke was not idling and then motor was not going over 4500 RPM. After $1200 paying my Suzuki mechanic found out stabi was clogging the fuel filter. The Suzuki mechanic said to use sea foam. I have been for since. Great stuff. I know it works because I has a lawn mower that was 15 years d and is was running bad. I put sea foam in tank and ran it in driveway. It runs like new. The smoke that came out.
 
Back
Top