Gas in crankcase - Kohler CV15 - advice, please

Discussion in 'Mechanic and Repair' started by pbdowling, Apr 29, 2006.

  1. pbdowling

    pbdowling LawnSite Member
    Messages: 2

    Mower: Husqvarna 48" walk-behind.
    Engine: Kohler CV15 w/ Walbro carb.
    Circumstances: Mower is 2 years old (previous homeowner use) has run fine. Problem occured with first start-up of season.
    Symptoms of problem:
    1. Checked dipstick - oil level appeared OK.
    2. Started engine 1st pull. Heavy white smoke coming out of muffler. Engine died after 10 seconds.
    3. Checked dipstick again - smelled of gasoline.
    4. Immediately pulled oil filter and drained crankcase, most of which was gasoline.

    Any idea what the problem is? How to fix it? Many thanks, comrades!
  2. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    Sounds like the float and or float valve stuck from sitting. The fix is remove carb. disassemble and clean with a spray type carb. & choke cleaner, Replace the bowl seal and float valve, Reassemble then replace fuel filter.
  3. pbdowling

    pbdowling LawnSite Member
    Messages: 2

    Many thanks, Restrorob! It looks like I need to pull the shrouds to get at the carb bolts. While I'm at the store picking up the bowl seal, float valve, and fuel filter, will I also need a carb gasket or other parts?
  4. oldrustycars

    oldrustycars LawnSite Senior Member
    Messages: 301

    wouldnt hurt to get any gaskets disturbed taking the carb off.
    and if i may add my 2 cents, im a firm believer in shutting the fuel valve off when you're done, especially when its on the trailer. i turn em off and run til it stalls. those big fuel tanks put lots of pressure on that little float, and everytime you bounce going down the road, a little fuel gets past the carb and into the oil. and any gas in the oil is bad.
  5. DT Lawn Care

    DT Lawn Care LawnSite Senior Member
    Messages: 850

    Hey, I know that this is a REALLY old thread, but I had the same problem with my CV15. YOU NEED TO PUT A GAS SHUT-OFF ON IT AND SHUT THE GAS OFF EVERY TIME YOU PUT IT AWAY. I have not had one single problem with that since. Something with that carburetor likes to let the gas flow into the crankcase as you say. Probably too late to help, but hey.
  6. Valk

    Valk LawnSite Silver Member
    Messages: 2,711

    Wasn't there a recent thread about faulty fuel pump diaphragms...this scenario sounds eerily similar.

    Also, I'm puzzled by the oil level being OK before startup...and then sounding as if the oil was replaced/displaced by the gasoline...could this happen w/in the 10 seconds it ran and smoked?
  7. DT Lawn Care

    DT Lawn Care LawnSite Senior Member
    Messages: 850

    What happened to me is when I was having these problems, I would take the air filter off and watch the carb. Well, first of all the air filter compartment part of the carb was FULL of gas. As soon as you pull the starter recoil, even just a little bit, the engine would suck the gas right into it (I guess straight into the crankcase). It puzzled me quite a bit, but like I said, the gas shut-off has completely fixed these problems.

    Oh, also, there is no fuel pump on these engines.
  8. RonAyersMotorsports

    RonAyersMotorsports LawnSite Senior Member
    Messages: 854

    It doesn't fix the problem. The problem is no seating between needle valve and seat on float. By shutting fuel off it just prevents any more fuel from entering carb. Problem still there you just prevent fuel to enter to cause the problem. In any case like this carb must be rebuilt.
  9. Valk

    Valk LawnSite Silver Member
    Messages: 2,711

    How easy and/or effective would a carb-soaking-cleaning and some compressed air...compared to a rebuild? Is this a parts' issue or a sediment issue?

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