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  1. #1

    Join Date
    Dec 2016
    Posts
    3
    Location
    Michigan
    Mower
    John Deere

    kawasaki fh491 on jd x300 gas in crankcase

    My John Deere X300 has a Kawasaki FH491V 2 cylinder engine. Recently I have been getting gas in the crankcase. So far I have replaced the fuel pump, as there is a hose from the pump to the crankcase which operates the fuel pump diaphragm. I am still getting an over full crankcase with a gas smell and the engine does seem to use more gas than usual.
    The problem still seems to be there. The engine starts and runs ok, other than a lack of power at times. In the summer, when I first activate the mower deck, the engine doesn't come up to speed right away and bogs down too easily. This problem comes and goes and may or may not have anything to do with the gas in oil problem.
    Any ideas.....................?

  2.  

  3. #2

    Join Date
    Aug 2016
    Posts
    79
    Location
    Washington
    Mower
    jd425AWS, JD L120, JD GT262, JD LT160, JD LT150, JD L110, LX188

    Re: kawasaki fh491 on jd x300 gas in crankcase

    check to make sure both cylinders are firing, this can come and go due to coil packs getting hot or other gremlins that cause them to fail intermittingling. If there is one that isn't firing, that can cause the gas to get into the oil. If the coils are fine, the carb could be having some issues and dumping too much fuel which would end up mixing in with the oil. Its easier to check the coil/spark plugs first before jumping into a carb, based on what you described?

  4. #3

    Join Date
    Nov 2014
    Posts
    6,763
    Location
    Australia
    Mower
    Victa slashers & Push , Rover Rancher II's, Cox ( several ) & White LT120 + GT 200

    Re: kawasaki fh491 on jd x300 gas in crankcase

    Your float valve is not cutting off the fuel which overflows down the carb throat and runs into the cylinder then down into the crankcase,
    Cheap work around is to fit a tap on the fuel line between the fuel pump & the fuel filter ( makes changing the filter easier too.
    urn the fuel off and let the engine starve out when you finish mowing

  5. #4

    Join Date
    Dec 2016
    Posts
    3
    Location
    Michigan
    Mower
    John Deere

    Re: kawasaki fh491 on jd x300 gas in crankcase

    Thanks for the ideas. I have ordered a carb kit which should be in Wednesday, but the more I think about it the more I think the problem may be one of both the cylinders not always firing. It would explain the lack of power at times. When starting to mow in the summer there are many times the engine does not come up to full speed when the pto is engaged. Under this situation if the grass gets thick the engine will bog down as well. Then later you can hear the rpm increase to normal. I have ruled out a governor problem or mixture too lean. A cylinder dropping out would explain my symptoms. A non-firing cylinder would also allow unburned fuel to get in the crankcase, a little at a time. Since replacing the fuel pump I have been checking the oil level frequently and it takes several days for the level to go up in the crankcase.
    Anyway, thanks much for the responses. I will post the results of my problem when I get it resolved.
    Paul Hoekema

  6. #5

    Join Date
    Nov 2014
    Posts
    6,763
    Location
    Australia
    Mower
    Victa slashers & Push , Rover Rancher II's, Cox ( several ) & White LT120 + GT 200

    Re: kawasaki fh491 on jd x300 gas in crankcase

    Pull the rocker covers off.
    Sounds more like a push rod bent or popped off.
    A plug not firing puts fuel into the muffler, not the crankcase unless there is no rings of a big hole in the piston.

  7. #6

    Join Date
    Dec 2016
    Posts
    3
    Location
    Michigan
    Mower
    John Deere

    Re: kawasaki fh491 on jd x300 gas in crankcase

    Braved the cold weather today and found only one plug had spark. Ended up replacing the one coil (almost $70.00 from J Deere). When I pulled the plugs, the non-firing plug was wet with gas. I will keep a close watch on the oil level for a while to be certain, but I think some of the unburned gas was washing down the cylinder into the crankcase. As I mentioned before, it took several days before the gas affected the oil level. Time will tell.
    One thing for sure, it sure moves a lot more snow through the blower now with 2 cylinders firing! What is crazy too is it is not really obvious from the engine sound when it is running on one cylinder. The mechanic at the John Deere dealership mentioned this too.
    At this point I am going to assume (assume - makes an *** of you and me) my problem is over, but will closely check the crankcase level for a while. Thanks again for the ideas and suggestions.

    Paul Hoekema

  8. #7

    Join Date
    Nov 2014
    Posts
    6,763
    Location
    Australia
    Mower
    Victa slashers & Push , Rover Rancher II's, Cox ( several ) & White LT120 + GT 200

    Re: kawasaki fh491 on jd x300 gas in crankcase

    I have an engine which I inherited from the previous owner,
    A water cooled Kawakasi V-Twin.
    Owner cam in complaining it did not seem as powerful as his old 17Hp single.
    It had been dealer serviced for 2 years and was then out of warranty so he did a swap for a 2000 series Cub which I still service.
    Bert found no compression on one side so pulled the head off.
    There was no piston or rod in that side.
    The motor came out & a Kohler went in.
    I also service that mower still going strong.

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