Whoa......lots of fuel in my Crankcase.....Skag.

Discussion in 'Mechanic and Repair' started by flintknapper, Feb 19, 2019.

  1. flintknapper

    flintknapper LawnSite Member
    Messages: 159

    Finished mowing my lawn the other day, parked the Skag and later that day decided I would sharpen the blades and do some other maintenance on it.

    It had been sitting 4-5 hours when I went to go work on it and I saw a huge amount of 'liquid' had been dripping from underneath it. At first glance it looked like engine oil and the drip was also coming from right underneath the engine.

    Upon closer examination the fluid was indeed oil BUT looked too thin. It was more fluid than the crankcase could ever hold and smelled like gasoline.

    So I pulled the dipstick and sure enough the level was about 1/2 way up on the stick.

    So I got a catch pan and removed the dipstick and body altogether and the fuel/oil mix just chugged out of it. :(

    It has never done this before and I have owned it since new (2003 model). I'm guessing the float valve in the carb is not closing off in its seat, or the float has filled with gas?

    I have a carb from a Kawasaki FH721V (mine is a FH601V) that will bolt right on and I've been meaning to do the 'carb mod' to raise the HP rating from 19 to 25 (I already have the oil cooler installed). But I suppose I need to go the Carb first (it is used).

    Need to get it up and running, the growing season in Deep East Texas is about 2 weeks away. Already have weeds popping up in the yard.

    Skag Engine.jpg
    hort101 likes this.
  2. hort101

    hort101 LawnSite Fanatic
    Male, from S.E. New England
    Messages: 17,105

    sounds probable
    try shutting off the fuel when not in use if you have a shut off
  3. Walker56

    Walker56 LawnSite Fanatic
    Messages: 9,988

    The needle/seat is either worn or has crud on it causing it not to seal. I would drain the oil/gas mixture and remove the filter and refill with fresh oil and new filter before you start the engine again.
    Here is a link to the service manual for both engines.
    Last edited: Feb 19, 2019
    AlohaMowing, kemco, sjessen and 2 others like this.
  4. OP

    flintknapper LawnSite Member
    Messages: 159

    Yes, the fuel selector valve does have an off position.

    I drained the crankcase after discovering the problem. Replaced the oil filter and refilled with new oil. The engine did start...but unsurprisingly smoked quite a bit, it got a little better after idling for a few minutes but then wanted to die.

    I'm guessing the crank case vent is likely saturated. So I will need to pull the flywheel and cover to get to that. It needs to be replaced anyway and I can check the upper crank seal while in there. I'll pull the plugs and clean them up next. Also do a compression test while I have them out.

    Thanks for the responses and information. It is greatly appreciated.

    hort101 likes this.
  5. OP

    flintknapper LawnSite Member
    Messages: 159


    Thank You for the link to the service manual. It will get me started. I had ordered one (paperback manual) just the other day to have for reference in the event I can rebuild this engine. I may just choose to re-power if too many components are out of spec.

    But I am hoping to press it into service one more season...then tear it down this winter and see where we are. It has been a good engine all these years and has probably given me all the service one could expect. I don't know the 'design life' of this engine, but I have probably well exceeded it.

    Thanks again for the help.
    hort101 likes this.
  6. Koehn's Lawn Service

    Koehn's Lawn Service LawnSite Senior Member
    Messages: 821

    What type of fuel pump is on this machine I have had this happen to my kohlers and the diaphragm would go bad letting fuel get by and filling crank case also have had plugs go bad fouled plugs but that would usually be from a bad fuel pump but replace spark plugs also
    ARN Greencare, zlandman and Walker56 like this.
  7. OP

    flintknapper LawnSite Member
    Messages: 159

    Never had much trouble with the fuel pumps. The present one was replaced last season...not because the old one wasn't working but the sintered bronze breather on them gets too dirty to keep cleaning.

    But I will take that under advisement and check that as well. Thanks.

    KAW fuel pump.jpg
  8. Walker56

    Walker56 LawnSite Fanatic
    Messages: 9,988

    @Koehn's Lawn Service , do you find the blown fuel pump diaphragm to be a common issue? I ask because I have never had a Kohler pulse fuel pump fail that way on any of the Walkers that I service.
    sjessen likes this.

    JLSLLC LawnSite Fanatic
    Messages: 13,867

    Walker56 likes this.
  10. rippinryno

    rippinryno LawnSite Bronze Member
    Messages: 1,364

    Very rare for that type of fuel pump to cause over flooding. It's certainly your carb and as you mentioned it's likely the float. Does your carb happen to have an overflow on it? Some do and some don't, if the overflow is clogged it won't do it's job, which is to let the gas go out the overflow rather that into the cylinder. I've had this happen on several engines, it's always the float. You could probably pull the carb and replace that and be fine, however if you have a backup carb, might as well slap it on.
    Walker56 likes this.

Share This Page