Which decarb procedure?

[eavega]

Okay folks.

This forum has great information and a lot of smart people whose opinions and instructions I have come to count on over the last few years. I'm gonna do a decarb of my 70 HP Johnson this weekend, and I had a little confusion. If you look hard enough, there are two good procedures for doing a decarb; one lives in the "Top Secret Files" thread under the Johnson & Evinrude threads, the other lives in the Outboards Frequently Asked Questions. There are subtle differences between the two (one just basically runs premix + sea foam through the motor at 15 min intervals, with 15 min in between and no need to replace the spark plugs, the other involves spraying sea foam directly into the cylinders and down the carb barrels, then taking the boat for a WOT run to consume a gallon of premix/sea foam, then replacing the spark plugs).

Can anyone share their experiences doing it either way? I'd rather not have to replace the spark plugs (the ones in there are brand new, and I didn't keep the old set so I would rather not ruin a brand new set of plugs), but if one way is better than the other, then so be it. Thanks in advance for the answers.

Rgds

 

[jonesg]

Re: Which decarb procedure?

Make a decision, either way is vastly better than broken rings.
My compression went from 70 to 80+psi.
I prefer spraying into cyl's, leave to soak 30 minutes then run and shoot more into the carb, causes less smoke but still works. Blip the throttle manually to keep it going.

You can see the carbon coming out in the exh wash on a hose, water turns grey, stop when it starts getting clear.
15 minute process.

 

[eavega]

Re: Which decarb procedure?

So, it doesn't matter which way to go. The basic process is "Sea-Foam thru the motor for a bit. Let it sit, run a bit, let it sit, Sea-foam, let it sit...Repeat until it stops blowing crud through the exhaust.

Change the plugs if they look nasty.

got it

-E

 

[mrcrabs]

Re: Which decarb procedure?

I use the J/E engine tuner, and follow the instructions.
I think J/E has the better product and much less convaluted selfmade instructions, who ever came up with the decarb BS must own stock in the seafoam company. I just don't have all day long to play a gallon of this and a squirt of that....engine tuner will pop out that carbon and clean them rings asap.....you can even buy it here at Iboats.

seafoam is nice fuel conditioner but why not use the product intended for the decarb of your outboard?

 

[SparkieBoat]

Re: Which decarb procedure?

do both.....get engine to operating temp..pull plugs..spray %100 sea foam into cylinders and let sit for 30 mins...then do the high concentrate gas can.

 

[emdsapmgr]

Re: Which decarb procedure?

It would be helpful to know the year of the engine. There is another procedural option on Bombardier engines that are mid 90's and above. OMC added a schrader vavle on the red lever of the primer solenoid. It makes it easier to apply the factory Engine Tuner (and also the factory fogging oil). The early primer solenoids did not have that feature (but it can be added for about $8.) If you have that valve, it makes it easier to run the aerosol tuner through the engine and as such may determine just which type of fogging can you wind up purchasing. Personally, I think it is really handy. It eliminates the need to pull of the airbox cover all the time.

 

[MichaelP]

Re: Which decarb procedure?

Ah Ha! Thanks emdsapmgr. When ever someone said spray in the carbs I was thinking...Hey I'm not about to pull that cover off for that! Now I know what that valve is for on my 1990 90 rude.

 

[Silvertip]

Re: Which decarb procedure?

So SeaFoam should be used ONLY as a fuel treatment eh???? Funny that many automotive service shops use it religiously to clean the intake system of carbon -- specifically IACs (idle air controls). This product is indeed excellent for carbon removal and if you use it as recommended for that purpose as well as on a regular basis as a fuel additive, you will only need to do this once every few years (if that). And it is cheaper than the engine manufacturers products as well.

 

[eavega]

Re: Which decarb procedure?

It would be helpful to know the year of the engine.

Yah, no. This motor is a 1976, so off will come the airbox cover!

Thanks for the suggestion, though.

Rgds

 

[boobie]

Re: Which decarb procedure?

I'll still stick with the BRP Engine Tuner and follow the directions on the can. Had very good luck with that over the years.

 

[JB]

Re: Which decarb procedure?

It really doesn't matter which of the several complex rituals you use. They all work, provided you anoint yourself with genuine stump water ahead of time and use an accurate stopwatch.

Or. . . .you could do what outboarders and Ford T and A drivers did back in the dark ages. Steam clean the innards of your engine. That is done with water, dripped into the carb(s) of a warmed up engine running under load. On the water works best. We did this regularly, as 8:1 and 16:1 mixes of 30W motor oil carboned things up pretty regularly. We dripped water until the smoke quit, then ran her a good 5 minutes more.

The new stuffs (and fancy rituals) are a lot safer and may even work better, but you can't beat the price.

 

[eavega]

Re: Which decarb procedure?

Does the iBoats marine shop carry Stump Water

Rgds

 

[emdsapmgr]

Re: Which decarb procedure?

One other tip for the older engines with the mechanical choke solenoid. Drill a tiny 1/8" hole in the plastic airbox cover at the center of each carb throat. Makes it easy to stick that aerosol tube in that hole, all the way into the carb throat, when fogging or using engine tuner. Now you don't have to pull the cover once or twice a year....

 

[JB]

Re: Which decarb procedure?

Does the iBoats marine shop carry Stump Water

Rgds

Stump water loses its magic as soon as removed from the stump. You gotta go in the forest (at night) and find your own stump.