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14 HP Kawasaki engine knock

Discussion in 'Mechanic and Repair' started by JSMLAWNCARE, Jan 31, 2002.


    JSMLAWNCARE LawnSite Member
    Posts: 137

    Has anybody heard to stop engine knock on a kaw. to spray either W-D or water, very small amounts on each, in the carb after the engine is really hot. I was told it would clean the carbon off the top of the piston, in return stop the slight engine knock.

    CPLLTT LawnSite Member
    from Oregon
    Posts: 17

    Thats an old timers trick. Water does not compress, so pouring it into the carb (in small amounts) while its running will act as tiny hammers breaking up the carbon deposits. It does work in old car engines, but on your engine the smart thing would be to pull the head and manually clean the carbon off.
  3. captdevo

    captdevo LawnSite Senior Member
    Posts: 932

    if it's knocking, cleaning the carbon off will not stop it, it may even make it worse.

    you've got bigger problems!!!

    i'd pull the head and see wher you have play, wrist pin, piston, rod or crank.......

    pouring ice water in a carb was meant for large horse power engines with a bigger bore.

    i've done this on older vehicles to free rings that where stuck by carbon and loosen stuck lifters.

    if you want to clean carbon build up on smaller 2 & 4 stroke engines, i would suggest using Mercury or OMC "Combustion Chamber Cleaner" availble at any outboard motor shop.

    i've used these products for over 12 years, they really work....
  4. 65hoss

    65hoss LawnSite Fanatic
    Posts: 6,360

    Pouring a little transmission fluid in a carb will also clean things out.

    BRIAN GALLO LawnSite Senior Member
    Posts: 282

    If you're talking about "run on" after the engine is shut off, simply get a bottle of Gumout carb cleaner (the stuff that you put in the gas) and let that run through. It does wonders for carbon build-up. But, if you're getting a lot of carbon I would check the carb. It might have a clogged jet, misadjusted floats or need rebuilt. Also make sure you have the right spark plug and heat range in.

    JSMLAWNCARE LawnSite Member
    Posts: 137

    Thanks for everybodies insights. I do believe the best thing to do is to take off the head and do some investigation. At least I have some time before I get busy!!
    Thanks again,

    Jim M
  7. Jay NineteenLM

    Jay NineteenLM LawnSite Member
    Posts: 4

    If your engine has lots of hours the knock may be from the crank counter balance. I have heard many of them hammer. If they get to bad they will knock a hole in the rear of block.
  8. khouse

    khouse LawnSite Bronze Member
    Posts: 1,465

    Can you tell me more about the knock? Low or high rpm? Load or no-load? Cold or hot engine? Did the knock start quickly or built up slowly? By running unleaded fuel there should be virtually no carbon build up in the combustion area unless the rings are bad and too much oil is entering the combustion area. I would agree with the other guys that you have a mechanical problem. Can you turn the crank back and forth fast by hand and hear or feel any free play?

    JSMLAWNCARE LawnSite Member
    Posts: 137

    I'm going to try to answer to the best of my memory. It's been 3 months since I used the mower. I have the mower stored through the winter at my parents place. A few weeks ago when I started it, it knocked at low RPMs. I didn't raise the RPMs up high and/or put it under a load. I always change the oil before I put my mowers away for the winter.
    It did blow a great huge cloud of white smoke when i started it up. I used sta-bil in it before I parked it for the winter. I guess I just didn't let it work through the system enough. I didn't change the sparkplug since beginning of last season. I only put less than 150 hours on the machine.
    I don't recall a knock under a load back in the summer. It did knock at low RPMs when I started it last summer. I'll have to get back to you after I change the plug. I also put it through the test.

    Thanks for asking. I'll write back as soon as i find out. "it might be next weekend"

    thanks again,

    Jim M
  10. thegrasscatchers

    thegrasscatchers LawnSite Member
    Posts: 11

    Did you check to make sure that you dont have too much oil in the crankcase? Just a check.

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