To decarbon or not to decarbon ?

[Roberthill]

Got a 1957 35hp Johnson and a 2000 90hp Johnson ,mostly use the older motor , but should I decarbon these motors ? I put Seafoam in the gas tank on the 2000 . What do I use and how if I should ? Thanks for any replies .

 

[Sea Rider]

To decarbon with Sea Foam inside tank will be a long decarbon process if never was used regulalry inside of tank. Better use OMC/BRD Power Tuner or CRC Engine Tuner sprayed through carb while OB is ON, works much faster and does an excelent job, OB will idle nicely along running much smoother. Follow can instructions. Should be applied every 100 worked hours to maintain top OB performance.

Happy Boating

 

[dingbat]

Pull the plugs and look at the top of the cylinder.
If it's shiny or "brown" don't bother. If it looks like charcoal then go for it.

1/2 can of sea foam and a 1/2 gallon of gas. Burn half the gas and let the motor sit for 15-20 minutes. Start again and burn the rest of fuel.

It with smoke like heck if it actually needed decarbed.

Take it out and run it like you stole it. Your done.

 

[Sea Rider]

When removing plugs won?t be able to check piston rings condition . Go for a complete combustion chamber decarbon yes or yes, won't harm the engine.

Happy Boating

 

[JimS123]

I have never decarboned the main, but used to do it on the kicker annually. I use my kicker extensively for idle speed trolling, hence I felt the need. Always used OMC Engine tuner. I have gotten lazy in my old age. Haven't gone thru the process in many years. The motor ran good when I decarboned it, and now it runs good since i stopped.

 

[oldboat1]

I've also done the decarb on a couple of trolling motors. IMO, though, running it regularly is just adding a solvent to your regular fuel, and I've never been sure a lot of good comes from that. I always wonder if in fact it could be harmful on anything non-metal (think fuel pump diaphragms, carb floats, maybe fuel lines). A lot of new listers seem to mention adding Seafoam as a regular habit from the git go, and guess I don't git that.

 

[MH Hawker]

i am a regular sea foam user, i am on a 9.9 lake so my fuel use is a lot lower than most around 150 gal a year and i add 1/2 oz per gallon and while i know its not needed it seams like the motor runs smother with it and for the last 7 years its 2 key bumps and running and off the slip

 

[dingbat]

Decarb dates back to the days of using regular 30 weight oil as a 2 stroke lubricate.

Modern 2 stroke oils have pretty much eliminated the need to decarb a motor in good mechanical condition.

 

[Sea Rider]

2 strokes OBs will always form carbon build ups inside combustion chamber to a certain degree, will depend on fuel octane and the quality of 2 strokes oil used, some form less carbom, some more. For the non regular sea foam users, will include myself, using Engine Tuner type products sprayed through carbs although won't remove carbom build ups completely which sticks very hard on piston heads, cylinder head, at least will make its job on piston rings for OB to run much smoother.

If sprayed at each 100 worked hours, much better, for what it costs, why not use it regularly. I feel a great difference on the throttle after its application.

Happy Boating

 

[Roberthill]

Thanks for all the comments . My biggest problem is finding the spray (OMC,BRD or the OMC) . Rings was my biggest concern . OMC dealer is a trip away so guess I'll go there .

 

[Sea Rider]

Other alternative : CRC Engine Tune-UP, check Iboats, Amazon. Works excellent.. For the record, post if OB runs much smoother before application or not ? Must go for a 1-2 min wot spin after application tu burn out all of product unburn leftovers. It's normal for OB to smoke worst than a gang of chinese poker players, playing cards in a close room. LOL!!

Happy Boating

 

[jimmbo]

Todays Combustion Chamber Cleaners are pretty lame. In the 60s and 70s OMC and Mercury had some awesome cleaners. The smell of them in the can was repulsive, and the smoke during application was truly eye burning. But they did work very well at freeing stuck rings

 

[Grub54891]

I've de-carbed a few that were being temperamental over the years, helped the idle and performance quite a bit. But these were neglected customer boats. I used a spray type, cant remember the name though. Back in the day at the farm, it was common to use water, slowly poured down a tractor or car carb, while it was running, steam clean. Pour it in for a bit, shut down and let soak. start up and watch the black junk come out of the tailpipe. Of course if you pour to fast you can hydro lock the thing and cause some pretty bad destruction.

 

[Roberthill]

In above post (#10) meant to type OMC,BRD and CRC ,my finger and my brain don't cooperate sometimes.

Will post results but allow me some time , wind blowing every day , won't let up .

 

[jimmbo]

Back in the day at the farm, it was common to use water, slowly poured down a tractor or car carb, while it was running, steam clean. Pour it in for a bit, shut down and let soak. start up and watch the black junk come out of the tailpipe. Of course if you pour to fast you can hydro lock the thing and cause some pretty bad destruction.

Works even today on four strokes. Not so much on two strokes

 

[Sea Rider]

See no difference in the OB's renewed agility using old or new Evinrude Power Tuner which is still available today. 2 strokes which are filthy engines need a piston ring decarbon from time to time if not using any other product as Sea Foam or equivalent pored inside tank to maintain piston rings in good working order.

Happy Boating

 

[JimS123]

2 strokes which are filthy engines need a piston ring decarbon from time to time if not using any other product as Sea Foam or equivalent pored inside tank to maintain piston rings in good working order.

Happy Boating

How do you explain 40+ year old 2-strokes that run perfect year after year and have never been decarboned in their lifetime?

 

[Sea Rider]

OB's if old or new which has never been decarboned before should run fine, carbon build-ups will not make any OB to miss or perform less. I'll bet that if those OB's receives a Power Tunner overdose spray through the carbs will run much smoother afterwords at idle and throughout the whole throttle range as when out of the box. For peanuts cost, why not use it ? You can only tell the difference after applying product as indicated.

Happy Boating

 

[Chinewalker]

How do you explain 40+ year old 2-strokes that run perfect year after year and have never been decarboned in their lifetime?

A lot will depend on the qualify of the fuel and oil used during the motor's lifetime. Also makes a difference HOW the motor is used. A motor that spends its life trolling and never getting really warmed up will develop more carbon than a motor that is run at its peak performance. Motors that are lugged (not able to reach top of the power curve) can also build up more carbon. Many factors involved in what motors build up carbon to the point of it being an issue and which ones don't.

 

[Sea Rider]

Chinewalker, + 2, technically explained.

Today was CRC decarbon time. Firstly decarboned both plugs to near new cond, then gapped both to specs

Warmed OB for 5 minutes. While geared, throttled to 2000-2500 rpm range, sprayed several shots of CRC Engine Tune-UP through carb's throat, let it smoke for some time till product cleared off, did same procedure 5 times in a row. Went for a morning wot spin on flat calm water cond, this is what happened.

Day before application, OB achieved with one up and lightly loaded 36 Km/H, after application 38 Km/H on a straight 1/4 mile water course run with GPS. Bear in mind that my boating is done at 4700-5500 rpm range from max 5900 rpm range, so one would assume that my OB runs carbon free inside, which is no, have dismantled it twice and know what's going on inside, LOl!!

On 2 strokes OB's. this product will not remove severe carbon build-ups, which must be removed mechanically stripping cylinder head & exhaust cover down, but will restore proven lost agility wonderfully. A must try.

Happy Boating