Only runs on Choke

Discussion in 'Mechanic and Repair' started by mopedal, May 6, 2007.

  1. mopedal

    mopedal LawnSite Member
    Messages: 7

    Hey Guys! I'm fairly new to the board but have been doing some reading on some different threads and you'll seem like great guys....always trying to help each other when you can!
    I've got a JD 175 with a Kaw FC420V. Spark plug looks good and was new a few months ago. One thing that does look odd though is it appears I may be missing a jet or mixing screw on top of the carb throat, it's the one on the right side just under the gov linkage.
    On the top left there looks like a jet even though I don't know it's function. (all the jets I've ever seen have gas going through them! Ha!) This one may meter unfiltered air for some reason...not sure.
    Anyway, does anyone have a link or a picture of this particular carb I can look at and try to figure out the problem? Also any suggestions would be greatly appreciated! Thanks Rick
  2. khouse

    khouse LawnSite Bronze Member
    Messages: 1,465

    If it only runs with the choke applied then you need to remove the carb. Then tear it apart and spray it out with a brake clean spray. Then blow it out with compressed air. Reassemble. Then flush the fuel cell and lines and change out the fuel filter. That should do it.
  3. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    [​IMG] [​IMG]

  4. Mark in MD

    Mark in MD LawnSite Senior Member
    Messages: 322

    I run these engines, and what you describe happens once in a while -- usually from dirt sucking in from the air cleaner somehow.

    Just take the carb off. Take the bowl off. Get a thin piece of steel wire and stick it in every hole you can find. Especially part 19/20 in the above diagram. Poke it all the way through. Put it all together and put it back on and you should be good to go.
  5. mopedal

    mopedal LawnSite Member
    Messages: 7

    Thanks for the diagram and info guys! I'll give it a try!
  6. mnstrohm

    mnstrohm LawnSite Member
    Messages: 11

    I've got the exact same problem, but on a 15HP FH430V. I was going to post the same question and it seems as if you guys know the answer. So here's my question: When you say to "tear it [carb] apart", is this something a novice can (or should) do? I have the Service Manual, but under Carb Disassembly it mentions thing like marking positions of pilot screw limiters and replacing pilot screws, etc. . . To be honest, this scares me. I can handle taking the bowl off and clearing clogs in the Nozzle Assembly, but should I completely remove the Carb? Thanks in advance.
  7. mopedal

    mopedal LawnSite Member
    Messages: 7

    I think you can do it! Just pay attention to what you take from where....clean the different parts...make sure none of the parts have any "fuzz" from the paper or cloth you cleaned or dried it with. OR take to your friendly small engine professional if you still don't feel like experimenting.
  8. mopedal

    mopedal LawnSite Member
    Messages: 7

    Well guys I took everything apart today...I've never saw so much junk in a carb. Looked like wood splinters or something. It was in every orifice of every jet or metering screw. All evidently came from an old gas can. The amazing part was the in-line filter evidently did nothing to catch this junk! It looked like it had no trash in it at all and took no effort to blow air through. It's like it wasn't even there...amazing!
    Anyway, it runs like a new one now! Thanks for all the help! Rick
  9. Mark in MD

    Mark in MD LawnSite Senior Member
    Messages: 322

    I don't know about your engine, but the 14 hp carb comes off in about 30 secs, and that's if you're slow. Remove air cleaner assy. Turn off fuel. Disconnect the fuel line. Remove two bolts. Remove carb from linkage. It's easier to take it off than it is to try to clear the "bleed pipe" as it's called with the carb still mounted to the engine.
  10. mini14

    mini14 LawnSite Member
    Messages: 236

    put the briggs 15 micron fuel filter on and u will be problem free.

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