Backfiring

Discussion in 'Lawn Mowing' started by HB Lawn, Sep 16, 2005.

  1. HB Lawn

    HB Lawn LawnSite Member
    Posts: 199

    I just finished my scheduled lawns for today and I need your to pick your brain alittle. Every time I started my machine today it would throw out small puffs of black smoke and as I gave it move speed it would start to act like it was starving for gas until it got to full speed and then it was ok. And then when I would shut it down, it would throw out a flame and back fire. What's the cause of this, any idea's?
     
  2. lawnmaniac883

    lawnmaniac883 LawnSite Silver Member
    Posts: 2,613

    Your engine is running too rich, black smoke=excess fuel. Starving for gas until full throttle, you sure it was not running too rich until full throttle? You may want to post a thread in equipment servicing and repair, restrorob can give you more insight as to the adjustment/cleaning/replacement of your carburator.
     
  3. Remsen1

    Remsen1 LawnSite Bronze Member
    Posts: 1,020

    I have to go with lawn maniac, your description of what the machine is doing doesn't match you notion that it's starving for gas. Based on your description I would lean toward the engine is flooded and takes a moment to burn off the excess fuel.

    A fuel starved engine sounds like "bwAAAAAAAAAA" when you give it throttle.

    A flooded engine sounds more like "put.........put........put..put.putputptptpt" gradually getting faster and faster, it starts off real smokey then the "put-puts" get quicker while the black smoke gets clearer.
     
  4. Remsen1

    Remsen1 LawnSite Bronze Member
    Posts: 1,020

    forgot one thing. If you thought it was fuel starved, were you then choking it? The excess fuel is what is causing the back fire. If you are choking, try starting without the choke. If you're already not choking it, then try letting the machine run at idle for 1-2 minutes before you shut it off. If it is still starting rich, then try starting it at 1/4-1/3 throttle. If this doesn't fix it then you should adjust your idle screw (have somebody else to this if you're not comfortable with it).
     
  5. ed2hess

    ed2hess LawnSite Fanatic
    Posts: 13,320

    On Kaw a real dirty air filter will give some of this symptom.
     
  6. HB Lawn

    HB Lawn LawnSite Member
    Posts: 199

    Hey I found out the problem. It was ALL due to "WATER" in my gas. Drained the gas tank and refilled it and everything is ok now. When I removed the air filter cover, water was everywhere. Not going to buy any more gas from that dealer again.
     
  7. lawnmaniac883

    lawnmaniac883 LawnSite Silver Member
    Posts: 2,613

    Perhaps we were mowing in the rain?
     
  8. HB Lawn

    HB Lawn LawnSite Member
    Posts: 199

    What RAIN. No rain here for weeks. ;)
     

Share This Page