Decarb with water

[Saboat]

I have read elsewhere on the forums mention of using water to decarb a motor.I have tried with the only decarb product available in our parts (Quiksilver Power-Tune) with some success (a lot of smoke),but the cylinders and piston tops are still not squeeky clean.<br />To use water to decarb would you run the motor at say 3/4 throttle and just spray a mist of water into the throats for a while ? Or is this just asking for problems in other areas like water in the bowl ?<br />(Motor is a 1989 40hp Evi)

 

[wayne h]

Re: Decarb with water

water will not go into the bowl is u spray it down the carb throat but i would no use water to decarb an engine stick with the stuff u buy in the stores u might wanna try some seafoam and keep mixing it with your gas at the end of the season u will see the diffrenc in your pistons.. carbon does not build up over night and can take sometime to get ride of. u dont wanna knock it all lose in 1 session anyway.

 

[umblecumbuz]

Re: Decarb with water

Wayne said:u dont wanna knock it all lose in 1 session anyway.

Why not? That's what the best decarb stuff claims to do! And that's what I've always done without any seeming ill effects.<br /><br />Must be a high-tech reason I've missed.

 

[rwise]

Re: Decarb with water

the bad part of using water to decarb a 2 stroke is water in the crank case.

 

[Saboat]

Re: Decarb with water

Unfortunately we don't have products like Seafoam available to us.I guess from the replies is stay away from the water and keep trying the canned stuff until clean.(Might take a couple of cans)

 

[rodbolt]

Re: Decarb with water

the very worst part is the fact that water ,when it rapidly expands, tends to steam clean the lubrication from the pistons and bearingsleaving them going up and down with no lubrication and an incredibly abrasive,corrosive substance in its place.. then if you dont run it long enough to clear the water from the crankcase it will cause major bearing/crank failure. so its not really high tech its more of a common sense issue. dont use water, and it will never be squeky clean. in fact squeky clean piston crowns are not what we want. mostly decarbing is to try to keep carbon from the ring grooves. a properley operating engine will mostly self clean the plugs and combustion chamber.

 

[JB]

Re: Decarb with water

We used to use water exclusively to decarb, Saboat. It was our only option to tear down.<br /><br />With engine at operating temp and about 1500-2000rpm:<br /><br />Spray water into the carb intake in amounts small enough that the engine does not start to drown.<br /><br />Continue for 5-10 minutes or until "smoke" turns from gray to white..<br /><br />Run engine at least 10 minutes after you stop the water. Pistons and heads should be squeaky clean. The water does not steam in the crankcase, it steams in the combustion chamber. Oil in the fuel will keep it off bearing surfaces as it passes through the crankcase.<br /><br />Because this is a topic generic to all non-DFI 2 stroke engines I am going to move it to Outboard Non-repair.<br /><br />Good luck.

 

[Vlad D Impeller]

Re: Decarb with water

In the old days a lot of the oldtimers decarbed with water, some of those motors are still running trouble free to this day, however this is not something for a novice to do, my advice to you is to stick with the mercury power tune or an equavalent product.

 

[timmathis]

Re: Decarb with water

I used to use water and alcohol! to decarb.

 

[wayne h]

Re: Decarb with water

the only reason why i dont decarb an old motor all in 1 shot is because i have seen and heard of carbon getting stuck in the rings and making a hot spot burning the rings and piston. this is just personal prefrance on how i do it thats all.

 

[gewf631]

Re: Decarb with water

Edlebrock used to sell a water injection system for cars (kind of a fancy windshield washer-type setup). I installed one on a '76 Camaro, and used-it for a couple years. The only thing I ever noticed was that my spark plugs were always squeaky-clean!<br /><br />Also, had an uncle that was quite the accomplished shade-tree mechanic (even had a winch up in that tree to pull motors). He always poured tranny fluid down the carb to clean-out the combustion chamber. Given that it has some lubricant qualtities, I'd almost go that route instead of water (at least in a 2 cycle).

 

[timmathis]

Re: Decarb with water

That Elderbrock water injection system set up was for high compression pistons. It was to help decrease spark-knock, So it could run A lower octane fuel.

 

[rodbolt]

Re: Decarb with water

do as you wish<br /> however I watched a tech buddy of mine blow a piston on a 3cyl johnson with a bug sprayer and water. on teardown the previously good compression motor had scuffed the pistons. something about putting water in the carbs at about 1800 rpm. it was squeaky clean on reassembly.<br /> if you must use water and its highly not reccomended, then at least run it on double oil and after decarbing run it above 1/2 throttle under a load for at least 1 hour. the crankcase only runs about 100 degrees and it takes a long time to get the water out of the crank case, especially the lower bearing . the fuel recirc system will move water to all the main bearings and other cylinders. two strokes dont like anything that fails to lubricate going past the pistons. they just dont like it. <br /> as far as the water injection on automobiles it only worked at or near WOT. and most folks did not go WOT for very long.<br /> chysler was about the last of the auto manufactures to have a factory water injection system. it was set up with a vacum valve to only work at or near WOT. we ran a set up on our camero running a very much modified 427. we actually found that we could pull some extra ponies with it due to the fact that steam expands more than gas. the key was in getting the proper amount in. to much and it cooled the fire, not enough and it was usless. but then they changed the class rules and we quit running it.seems anytime someone figgured out an edge they changed the rules .<br /> but modern engine manufacturers take great steps in keeping water out of the airbox for a reason. water spray is rather hard on them. water is very abrasive under pressure and heat. there are to many better chemicals that cause no damage that are cheap. and that nice thin layer of carbon will actually insulate the piston crown somewhat and lower the wristpin area temps. its the rings job to transfer the heat of the piston to the cyl walls for cooling.<br /> the incoming fuel/air charge and the contact of the piston rings to the cyl walls is what keeps it alive. if we are lucky the piston never really contacts the cyl wall.<br /> we did the tranny fluid trick for years<br /> even had the fire dept called out once. after that we would notify the station before we did it.<br /> but I am with JB. years ago with 3 ring pistons and lower bushings and no lower bearings and not much in the way of decarb chemicals it was about it other than manually scraping them. however water will not decarb the rings. and that is what needs it the most. a good running well tuned engine wont need a cyl decarb. some engines are prone to clogging the exaust with carbon though. some of the worst were the 3 cyl lost foam cast merc blocks. many of them we had to pop off the power head and scrape at the end of each crab season. it would get so bad that no amount of chemical would help.