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air in line, choke closed, or just real thirsty?

Discussion in 'Mechanic and Repair' started by dakota2112, Jul 25, 2008.

  1. dakota2112

    dakota2112 LawnSite Member
    Messages: 55

    Brand new Scag Tiger Cub, 52" 25HP Kohler. I put about 2 gallons in the left tank, right tank is bone dry. Ran great for about an hour, then it stumbled and quit. I thought "there's no way it burned 2 gallons in one hour", but sure enough the fuel level was below the line-of-sight looking in the tank filler. I don't know if it actually ran it dry or not, but I added more fuel to the tank. While I was at it, I added fuel to the right tank, in case the problem was the valve sucking a little air from the empty tank. After more cranking than I was comfortable with, it finally started back up and ran fine.

    I also noticed that the choke lever runs out of easy travel by about the halfway position... that is, the choke is closed when the lever is full up, and the choke is open when the lever is about halfways down... and the lever won't go all the way down without forcing it. The carb end of the cable doesn't move when I do force it down, it just flexes the cable. I was running the engine in what I considered to be full open choke, at that halfway position on the lever.

    So I see three possibilities as to what happened...

    1. The tank valve started sucking air out of the bone-dry tank (dealer warned me beforehand that this could happen)
    2. Maybe I was running with the choke partially closed, drinking more fuel than it should
    3. Maybe it's actually thirsty enough to burn 2 gallons in one hour? At that rate, this machine would burn through two full tanks in four hours. I thought it was supposed to run all day fully loaded.

    I will keep both tanks full or at least partially full from now on, but I'm still wondering about that choke, like maybe it needs to be adjusted. Any thoughts?
  2. topsites

    topsites LawnSite Fanatic
    Messages: 21,653

    All of mine have the same problem...
    I put gas in it, hours later it's gone.
    Then I put a little more in it, and that disappears too.
    All this time I'm just minding my own business, not doing anything wrong,
    so why does the gas disappear, what the hell is wrong here?

    Seriously thou...
    2 gph's is what my 25hp Kawasaki consumes, always has, them Z's are thirsty hogs.
    On a side note, I almost never let either tank get much below 1/2, I do think the
    gas consumption is odd it does seem to suck more out of one than the other and
    what have you, so I keep them topped off.
  3. dakota2112

    dakota2112 LawnSite Member
    Messages: 55

    lol @ that

    Maybe these things are just that thirsty. Still a little surprised though since at this rate it'll only go half a day fully fueled. More testing to be done of course :)

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