I think I have bad GAS!

Discussion in 'Lawn Mowing' started by Guardian, Mar 20, 2002.

  1. Guardian

    Guardian LawnSite Senior Member
    from Florida
    Messages: 269

    I'm not sure, but I think I have a bad gas problem. This morning when I cranked up..There was all this black smoke and spittin 'n sputtering. (Like I had my choke on...but didn't)

    It was loud and offensive - and I know it was bothering my neighbors. Anyone else have this problem?

    Probably just me:(
  2. LawnLad

    LawnLad LawnSite Senior Member
    Messages: 738

    Assuming a 4 cy engine. Colder morning on choke so your mixture is rich. Too much carbon in the exhaust since the gas didn't burn completely - hence, running to rich. Not enough air!

    On our old 17 hp Kawasaki's - if we didn't shut the gas off between properties, or let the mower sit for a while, the gravity feed tanks put too much pressure on the needle and seat and would wear them out allowing excess gas to leak and accumulate in the cylinder. If too much got in and flooded the cylinder, you'd have to remove the plug, pull the recoil 20 times to dry it out and replace the plug. If it had not gotten to this point, we'd get a bunch of excess white and then black smoke as there was too much gas to burn all at once, then it would burn off and be okay.

    If the smoke is more blue and constant - could be oil leaking around the rings and getting into the cylinder.
  3. ceaman

    ceaman LawnSite Member
    from Indiana
    Messages: 131

    That hapens to me when I eat chilli :blob2: ...... I usually don't have any neighbors complaining though.:blush:
  4. mdb landscaping

    mdb landscaping LawnSite Silver Member
    Messages: 2,205

    Usually if you get bad gas, the motor will turn over and then stall frequently, or if theres any water in the gas, your motor will not run at all after an initil start. Sounds to me like you have an air intake problem like stated above. Of course im not in your shoes, and you could very well have some bad gas.
  5. awm

    awm LawnSite Gold Member
    Messages: 3,354

    sounds like the choke linkage may need lub at the carb.
  6. stslawncare

    stslawncare LawnSite Bronze Member
    from DE
    Messages: 1,484

    stop at the drug store they can help u out :D
  7. GilbertJT

    GilbertJT LawnSite Member
    Messages: 30

    Hey Lawnlad, I have a 14hp Kaw that I had the same problem with. I now shut that gas off every time. Have you rebuilt the carbs or anything to see if that would help. I ended up draining the oil, because I feared that some of the gas had drained back in the crank case. Mine actually was spitting gas out the exhaust when I pulled it over. I did the same pulled the plug pulled it a bunch of times and then it fired up and smoke a white plume for a while. It ran fine just need to burn that gas out.
  8. LawnLad

    LawnLad LawnSite Senior Member
    Messages: 738

    Gilbert -

    I was wrong, the problems were with the 14 hp Kaw's... not the 17.

    If we left the engine unattended for a short period of time, and we could pull the recoil, though it would be tougher than normal, we could get it going. If we could pull the recoil and get movement in the cylinder, but it didnt' want to start, we'd pull the plug, air it out and then get going. If we left the engine for a while - couldn't pull the recoil since the cylinder was full of gas, we'd have to change the oil, replace the plug, etc.

    We tried new needle/seats for the carbs. They wore out quickly due to the gravity tanks - too much pressure on the needles if we didn't shut the gas tanks off. So - we had to shut the gas off any time we trailered the mower or would leave it sitting for more than 10 or 15 mintues while off.

    We didn't find a solution for it and the vendor and the mechanics had no solution either - just poor design of the carb and fuel system I guess.

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