jlo440 seems to not want to run

  1. Welcome to 6x6 World.

    You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

    If you have any problems with the registration process or your account login, please contact us. Looking forward to seeing you in the forums and talking about AATVs!
+ Reply to Thread
Page 1 of 5 1 2 3 ... LastLast
Results 1 to 10 of 50

Thread: jlo440 seems to not want to run

  1. #1

    jlo440 seems to not want to run

    hello everyone,

    i just finished rebuilding my jlo440 and installed it back in the bigmax. i tried to start it but cannot get it running. if i spray ether im the carb, it will run...but even with fuel coming back to the carb, it jsut does not seem to want to run. the battery is dead so i am cha rging it now...just have been pull starting it...and pull starting it...and pull starting it.

    the carb is a walbro wr as I recall. it h been completely rebuilt last year...all new diaphragms etc.
    it does seem to be pumping fuel...but seems like there is air in the return line...is it sucking air?
    i have all brand new intake gaskets and phenolic spa cers between the intake and the engine and new gasket betweenthe intake and carb.

    where should i set the idle screw on the carb as a starting point?

    thanks
    chris

  2. #2
    Join Date
    Jun 2007
    Location
    Buffalo, NY
    Posts
    6,442
    Chris, First off, how is the spark? Did you try putting new plugs in? I personally would get rid of the Walboro carb........those and Tillotson carbs are just way too unreliable and sensitive. I'd use a 32-34mm Mikuni roundslide instead. You can find them on ebay off old snowmobiles pretty cheap.
    "Looks like you have a problem with your 4 wheeler........you're missin' two wheels there"

  3. #3
    Join Date
    Dec 2011
    Location
    Ontario Canada
    Posts
    672
    If it starts with ether than you have spark.
    Did you set the timing when you assembled it.
    Set the needles at 1 turn open till you get it running.
    Make sure there are no leaks in the fuel line.
    Air bubbles in the return line are normal till its running.
    Spray a gas oil mix into the carb instead of ether.(if its a 2 stroke)
    If you flood it pull the spark plug and dry it and crank it over without the plug in to clear the cylinder of fuel..
    Dont use the choke if you spray gas or ether in the carb.
    If you have good compression and spark at the right time and fuel it should
    start.
    Set the idle screw so it just starts to open the throttle plate.
    Keep pulling ...

  4. #4
    Hi Bazoo guy.

    Yes, it will start on ether...and do not want to continue to do that..especially with a fresh engine. It is a 2 stroke.

    There are two needles on it...an idle screw and I guess a high speed needle.

    Another question>>>> out of the Stator plate there is a brown wire..it is a ground. It is inserted in the female plug. On the wiring harness from the ignition switch etc, there is NO brown wire in the male plug coming from the ignition switch, wiring harness etc.

    Is there supposed to be a brown ground wire? Otherwise, how would one kill ignition and stop the engine?

    I will look for a Mikuni 32-34.

    Thanks
    Chris

  5. #5
    Regarding the Mikuni, since the Walbro is a diaphragm style pump, would I just put a vacuum powered pump (like on a B@S engine) inline? is that what others have done?

    Thanks
    Chris

  6. #6
    Join Date
    Jun 2007
    Location
    Buffalo, NY
    Posts
    6,442
    Quote Originally Posted by chris lewis View Post
    Regarding the Mikuni, since the Walbro is a diaphragm style pump, would I just put a vacuum powered pump (like on a B@S engine) inline? is that what others have done?

    Thanks
    Chris
    That's exactly what you would do. Something like this would do the job:

    VINTAGE MIKUNI FUEL PUMP RACE KART SNOWMOBILE SINGLE 1CY McCULLOCH ROTAX BRIGGS | eBay
    "Looks like you have a problem with your 4 wheeler........you're missin' two wheels there"

  7. #7
    Join Date
    Dec 2011
    Location
    Ontario Canada
    Posts
    672
    The brown wire is a ground from the stator. It should be grounded all the time.
    The ignition switch connects the 2 black wires from the coils (in the off position) to kill the ignition.
    You should pull the spark plugs and turn the engine over to prime the carb untill you see fuel flowing thru the return line.
    Heres the walbro manual.

    http://wem.walbro.com/distributors/s...viceManual.pdf
    Last edited by Bazooo guy; 02-24-2012 at 03:18 AM.

  8. #8
    Thanks for the info on the brown wire. I will need to jump that brown wire since the male plug did not have a receiving connector in it for the wire. That is a bear to get to while the engine is in....hmmm.

    I did figure out that the plug was partially disconnected on the ignition switch...hence it would not kill ignition. I plugged it in and there is no spark when the key is in the off position.

    There is fuel flowing into the filter on the carb (it has a plastic filter that screws onto the base of the carb. There is also some gas (with bubbles) making its way back out of the carb on the return line to the tank....so it is primed....just seems to not want to be pumping gas into the intake.

    Thanks for the WLABRO carb manual! SWEET!

    Chris

  9. #9
    Join Date
    Dec 2011
    Location
    Ontario Canada
    Posts
    672
    Do a compression test on the cylinders or cover the intake of the carb with you hand when its cranking and see if its sucking air.
    I think that engine has reed valves that could possibly be leaking?
    It should run without the brown wire connected.
    You can run it without the plug to the switch.
    The magneto and secondary coils produce the spark ..... the wires to the plug are for charging the battery or for lights and the kill switch.

  10. #10
    Join Date
    Jun 2007
    Location
    Buffalo, NY area
    Posts
    2,968
    There are no reed valves on a JLO....

+ Reply to Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts