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Carbon under valves

Discussion in 'The Hokey Ass Message Board' started by ROADMACSTER, Aug 1, 2009.

    Joined: Feb 14, 2007
    Posts: 57


    Has anyone ever tryed to clean out carbon in their engines by pouring a hand full of rice down the carb? Iv'e never tried it but heard an old hot rodder talk about it back in the sixties. Seems like you would be taking a chance of bending a valve, but as I remember the guy said it wouldn't hurt the engine.
  2. I've heard of the rice thing, also plain water and even Pepsi. Of course all of the above with the motor running. I worked in one shop where they would do the water trick to "blow out the carbon" once in a while.

  3. snapper
    Joined: Jan 4, 2004
    Posts: 531

    from PNW

    Water works , BUT can also damage your engine , I would give BG 44k a try,(blk can) Has carbon softers , then use the fuel additve has blaster additives.(red bottle) Yes it really works.
  4. Iceberg460
    Joined: Jun 6, 2007
    Posts: 880


    Sure does, fixed more then a few driveability concerns our dealership with the BG cleaners...

  5. In a way I can kind of convince myself that the rice thing might work, but it seems like one of those "last resort" kind of solutions. Like when you've got nothing to lose if it does more harm than good.:mad:

    Plus I'd be concerned about the possibility of the rice maybe causing the throttle to hang open and not return to idle. Sounds more like a method to try on someone else's car.:D

    The "water blasting" does work on some jobs if done properly with little risk of damage. But I'd guess that it's most effective at cleaning the combustion chamber and not the backside of the intake valves. If you've ever seen an engine with the head off that had a leaking head gasket that allowed coolant into a cylinder, you'll see how clean it leaves the top of the piston and combustion chamber.

    To try this "steam cleaning" method make sure the engine is fully warmed up and remove the air cleaner. While revving the engine, slowly trickle a stream of water down the carburetor. You don't need to wing it to wide open throttle, just enough to prevent the engine stalling and to blow any dislodged carbon out the exhaust. You can use an empty beer or pop can to pour the water from and try to keep the stream about the size of a pencil. You don't want to add too much water so quickly that you hydraulic the engine by trying to compress a big gulp of water!:eek: Actually, using one of those sport drink bottles with the "squirt cap" might make it easier to control the water flow.

    Oh, and make sure to do this outside with the exhaust pointed away from your open garage. This makes a mighty impressive cloud of steam and smoke. Expect a visit from the neighbors, if you still have any!:rolleyes: Or invite one of them over to hold his hand near the tailpipe while you're doing this. If his hand is peppered with bits of hot, glowing carbon, you'll know it's working!

    There are other products that will probably work better at cleaning the back of the intake valve. With some, you'll actually stall the engine out by pouring the stuff down the carb of the running engine at operating temperature. Then you let it soak for a few hours to soften up the deposits and restart the engine to clear the gunk out. But you'll probably want a fresh set of spark plugs on hand cause you're likely to foul out a set of plugs in the process. Also do this job outdoors and expect a visit from the neighbors.:D
    Joined: Feb 14, 2007
    Posts: 57


    Well I tried the steam clean and your right made a hell of a difference. Couldn't find the BG 44 so bought sea foam penatrant. Says it will do the same thing and have always heard good stuff about seafoam products. Well I sprayed it down going to grab a nap and then see if its made any difference. Theres a car show in down town Augusta Ks today so may try to drive it down there later. Thanks for the info guys. You know theres a wealth of knowledge here on the HAMB just for the asking.

  7. Lunatic
    Joined: Sep 28, 2004
    Posts: 1,199

    from Carson,Ca.

    LMAO ...riceburner?I use to watch my friend pour a quart of transmission down the carb (while running engine above idle)on every car he bought from the auction,it smoked for awhile then ran real good after that
  8. Crease
    Joined: May 7, 2002
    Posts: 2,878


    Not very intuitive, but water works quite well and is actually pretty safe.
  9. btmatt
    Joined: Nov 15, 2006
    Posts: 227


    Rice??? Do you get puffed rice out the pipes? J/K. I have done the water trick many times and it cleans the combustion chamber well, but not so well above the intake. I am a big fan of sea foam especially for 2 stroke dirt bikes. It really does a number on crudded up carbs and carbon in the exhaust port.
  10. A quart of Transmission? Dam, how did he get it through the carb?:eek:

    Just joking man, I know what you mean.

    I have heard the water one before, a bit of CDF (Common dogfuck sense, an Army term!) and it should work. Though I'm not sure it would atomise that well and some will be cleaner than others.
    Short of a tear down I guess this is your best bet.
  11. Tony
    Joined: Dec 3, 2002
    Posts: 7,350


    Same here. It's stuff that actually works!!
  12. RodStRace
    Joined: Dec 7, 2007
    Posts: 2,559


    Water works in the combustion chamber, BG (the pro 3 pack) does amazing things!
    Rice I wouldn't even try. Sounds like something an old timer would tell a young punk just to see how gulliable he is....

    Way OT, but ever see the Walter Matthau movie A New Leaf?

    At the start of the movie, he has lots of issues with carbon on the valves.

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