Decarbing for idiots

KTorian

Cadet
Joined
Aug 16, 2003
Messages
12
I'm getting ready to decarb my '85 Force 85hp. I've read the instructions in this forum, and I have a Clymer manual. What I can't seem to figure out is exactly where to spray the decarb. I have 3 carbs on my engine. What, if anything, do I have to disassemble to get to the carbs, and where exactly do I spray the decarb spray?
 

The Marine Doctor

Commander
Joined
Jul 25, 2003
Messages
2,177
Re: Decarbing for idiots

Decarb is to be sprayed through the throat of the carb. The large hole in the front of the carb. Let the engine warm up. Raise the idle to around 2k ish. Spray the contents of the can equally..or near equal into each carb. If the engine stalls while doing this restart it and continue.<br /><br />Let the engine sit for a few hours...longer if you like.<br /><br />Then take the engine to the lake and drive it WOT wide open throttle.<br /><br />TMD
 

MurdockJr

Petty Officer 3rd Class
Joined
May 14, 2003
Messages
97
Re: Decarbing for idiots

Also remove the spark plugs and spray into the cylinders. Let it sit over night than take the boat to the lake and run the hell out of it. Maybe Roscoe will pop in here he has the whole procedure. :) :)
 

KTorian

Cadet
Joined
Aug 16, 2003
Messages
12
Re: Decarbing for idiots

I did it this afternoon so I'll take it out tomorrow and see what happens. I didn't do the cylinders because I didn't get the last message in time. I'll see if there is any left that I can spray in the cylinders in the morning before I go out. Worth a try. My plugs have been getting fouled pretty badly, black and wet (cold fouled?), and I am hoping that the decarb will help.
 

gss036

Commander
Joined
Jan 18, 2003
Messages
2,914
Re: Decarbing for idiots

I picked this up some time ago on another board and have used it several times, works great and easy to do if you have a small tank w/same fittings at your O/B.<br /><br />Tip for the Week <br />Do-It-Yourself Engine Tip; A Simple and Cost Effective Way to De-Carbon an Outboard <br />By Capt. Bob Dunkelberger dunk75@comcast.net <br />This works for Carbed, EFI, Ficht, HPDI, Opti-max and even 4-strokes... and should be administered after every 50-60 hours of use. <br />First you need a separate small fuel tank. One of those 3-gallon red Tempos works well or an empty gallon milk jug in a pinch, but it might be a bit messier. <br />I use Seafoam over the OEM (original equipment manufacturer) stuff like OMC Engine Tuner or Mercury Power Tune. Note: 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 does the job in 15 minutes and can be purchased from NAPA, Car Quest or other auto stores. <br />You'll need 3/4 gallon of gasoline and one 16oz can of Seafoam for each engine. Don't forget to add 3oz of oil if you are pre-mixing in a carbed engine. Use a 3 ft piece of fuel hose off the small tank. Connect this tank to your engine by pulling off the main tank fuel hose from the intake side of your water separating fuel filter and plug the hose off the small tank onto that fitting. Or you can separate the fuel line on the tank side primer ball, so you can still use your primer. If your engine has a fuel plug then you will also need a fuel plug on the smaller tank's hose. <br />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 gets loaded with the Seafoam. Run the engine 15 minutes at the dock or just cruising around under 2500 rpm's. Then shut it down and let it sit for another 15 minutes. <br />Restart the engine; the smoke you see is the carbon burning off. Do the whole thing again and let her sit again for 15 more minutes. If she smokes after the second time do it again. <br />I've never seen one still smoke after three doses. (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) <br />The gallon mix should be just enough to do this 3 times. You don't need a wide-open throttle and you don't need to change the plugs. The plugs are cleaned at the same time as the combustion chambers. My suggestion is that every 50-60hrs is the optimal time to change plugs in most engines. <br />I cleaned an antique Evinrude once that had a 1/4" of solid carbon on the exhaust chamber walls by running a 1/2 gal of the aforementioned mix through it. Seafoam, a great product, has been around since the 1930's and it's what they used when they were burning straight 4 stroke 40SAE oils in outboards. <br />For you guys with the 4 stroke outboards? Those engines work 10 times as hard as any auto engine ever will and they too will carbon up. 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. <br />For those guys that like to work 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 and notes on the can, "Oxygen Sensor Safe". After that, if your engine manufacturer recommends a daily additive treatment then do so. The tank and hose are a one-time purchase and the Seafoam is only costs $5-6.00 per can.
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,667
Re: Decarbing for idiots

Decarb Process:<br />Your intent is to REMOVE the existing carbon buildup from the cylinders, heads, and rings, a spray decarb solvent product, such as SeaFoam Deep Creep, is needed to do the decarb process. Some people use one can per cylinder. Free moving rings are what seals your cylinders and gives you compression. Compressed and stuck rings equals loss of compression, and eventually, engine failure.<br /><br />Run engine at fast idle, with engine running, slowly spray liberal amount into each carb, its gonna smoke up the place,<br />spray for a couple minutes, now spray a larger amount into carbs until engine chokes out and stops.<br /><br />Remove spark plugs and spray decarb liberally into each cylinder, install the spark plugs, let it soak for an hour. <br /><br />Start the engine and run at medium throttle, or if at the lake, run it at full throttle. It won't hurt to spray some more through the carbs. Run it for atleast 10 minutes to flush the crud out of your engine. Now remove and clean, or replace the spark plugs. <br /><br />It works well to do the spraying, the night before you go to the lake. This way you can let it soak overnight, and really flush it out at the lake.<br /><br />Don't do this in front of the garage door or the house, unless you want it coated with greasy crud.
 
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