How bad is this?? Exmark gas and oil mixing!

Discussion in 'Mechanic and Repair' started by cariboulou, Aug 18, 2011.

  1. cariboulou

    cariboulou LawnSite Member
    Messages: 160

    My employee complained about my Exmark 32" pouring gas from the carb. It has a Kawi 12.5 hp on it. I took it from him and found that there is a LOT of gas mixed with oil coming from the exhaust port. I took carb assembly off and took off a cover with a breather of some sort to expose both valve springs and seals I think. There was a lot of gas and oil mixture there too. I checked the dipstick and it is very low on oil and smelled like fuel. What do you guys think is the main issue here? Should I look at piston rings or valves or valve seals, etc... Thanks in advanced for any help.

  2. topsites

    topsites LawnSite Fanatic
    Messages: 21,653

    The only thing I know for sure is you can not run it at all
    or you will tear it to pieces with fuel in the gas.

    Now I was thinking head gasket but it's out of my area of expertise.

    If it's pouring gas from the carburetor it could be as simple a thing as the float being stuck open,
    letting the fuel flow through after the bowl fills up will get it to mix with the oil...
    Oddly enough that would also make it difficult to start and fuel would spit out of the muffler initially as well,
    plus it would leak fuel throughout the night, you might take another look at it in the morning and see...
  3. Gianninilandscaping

    Gianninilandscaping LawnSite Member
    Messages: 53

    i would drain the oil, take the carb off inspect the float and see if it has gas in it. if not i would replace the needel and seat and put it back together and put the drain plug in, ( do not fill oil or run machine) turn the fuel valve to open and leave it sit overnight in the morning take the drain plug out and see if any gas comes out of the crank case, if not put oil in it and your ready to start cutting. if gas comes out that meens that the float could be bad and replace it...
  4. Mark Oomkes

    Mark Oomkes LawnSite Fanatic
    Messages: 15,128

    Just had this on an old Kohler, needed a new carb assembly and an oil change.

    All is good. Except the pocketbook. But, the mower is 7 years old, so I guess I can live with a new carb.
  5. White Gardens

    White Gardens LawnSite Fanatic
    Messages: 6,776

    Never really messed with a Kawi on repairs, but it sounds like there is a seal between the carb and block that is shot and allowing fuel to get in there.

  6. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    ^^^^^^^^^^^ Has the winning answer...... :clapping:
  7. cariboulou

    cariboulou LawnSite Member
    Messages: 160

    Well sort of followed Gianni's advice. Drained all oil/fuel from engine, even lifted it up sideways! Took carb apart cleaned with carb cleaner and compressed air, but I refilled oil and new filter and reinstalled everything. Seem to start ok, and smoked a little probably due to leftover fuel/oil in exhaust system. Will run for a little bit more and check oil level tomorrow. Cant really smell if any gas is on dipstick since oil is brand new. Wish I had read this before I did oil change, but no worries hopefully the carb was the problem. BTW, there was fuel in the fuel bowl but the carb didnt look really dirty. I cleaned the needle and i unscrewed the Jet?, the thing in the center of the carb and you can unscrew with a slotted screwdriver and made sure tiny hole in center was clean. How do you clean the seat, where the needle goes into?
  8. piston slapper

    piston slapper LawnSite Platinum Member
    Messages: 4,333

    Use a Q-tip with carb cleaner on it to clean the seat.
  9. cariboulou

    cariboulou LawnSite Member
    Messages: 160

    actually just got done draining oil again,but not filter, and going to see if there is gas in crankcase tomorrow. thanks for the advice, hope this does the trick!
  10. Gianninilandscaping

    Gianninilandscaping LawnSite Member
    Messages: 53

    glad it worked for you... try to trailer the machines with the fuel shut off... i have a lot of problems with customers at my work (equipment rental place, my full time job) not shutting the gas off then its bouncing around on the trailer and the float bounces up and down and floods the motor then you go to pull it over and it just locks up if theres enough gas in the cylinder... i always shut my machines gas valve off when i put it on the trailer and let it run when i get the trimmer and start the trimmer then i shut the mower off. saves a lot of time pulling the plug and wasting gas

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