14.5 Briggs i/c MTD 42" Won't continue to run/idle.

Discussion in 'Mechanic and Repair' started by frankrizzo, Jun 18, 2007.

  1. frankrizzo

    frankrizzo LawnSite Member
    Posts: 7

    Hello,

    I'm trying to assist a friend. He has an older (7-10 years old) 14.5 Briggs i/c MTD 42" that won't continue to run/idle. It starts with gas/starter fluid, but dies after word very quickly. I took a compression test and it's holding at 90LBS. When it does start, it does not smoke.

    We swapped out two different carbs. Cleaning both and soaking them in carb dip for 48 hours. Rebuilt and installed. Again, it will only start with assist from starting fluid or splash of gas.

    Now here is the tricky part, on a hunch i shoved a rag in the breathway of the air cleaner. Really restricting the airflow. Much more so that the choke does, but still allowing some air to pass. Bingo It will run like that. Accually runs pretty well too. I can actually get it to almost idle. I checked for vacuum leaks or cracks on the intake (this one is aluminum) and I can't locate any..

    Any ideas?
     
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

    What's the model & type numbers off the engine ?
     
  3. frankrizzo

    frankrizzo LawnSite Member
    Posts: 7

    Working on getting that info..Should have it a little later today.

    When we went through both carbs, I made sure all the jets were removed, and any passageways were clear. I was a little shocked that it ran when i was choking the crap out of it with the rag.
     
  4. sundiver

    sundiver LawnSite Member
    Posts: 1

    model # 287707
    Type: 0153-01
     
  5. Bill Kapaun

    Bill Kapaun LawnSite Senior Member
    Posts: 911

    Is this a gravity fed fuel system? IF so, are you using the RED filter?
     
  6. frankrizzo

    frankrizzo LawnSite Member
    Posts: 7

    It is gravity fed, by red filter I'm not sure what you mean. If I recall I've seen a red filer that is rather saucer shaped and is "short" on another tractor. This does not have that kind of filter on it. Seems to be maybe a generic "basic" small filter. I am sure the carb is getting gas though. Every time I remove the anti fire back valve from the bowl, a decent amount of fuel drains out.
     
  7. frankrizzo

    frankrizzo LawnSite Member
    Posts: 7

  8. Bill Kapaun

    Bill Kapaun LawnSite Senior Member
    Posts: 911

    Go to the Briggs website and download the IPL-
    http://www.briggsandstratton.com/display/router.asp?docid=78484

    Make sure the main jet is clear. Part 117/118
    Is this the Nikki or Walbro carb?

    "We swapped out two different carbs"
    They list different carbs for gravity feed or fuel pump engines....
    If you are using a "pump" carb on a gravity flow engine?????????
     
  9. frankrizzo

    frankrizzo LawnSite Member
    Posts: 7

  10. Bill Kapaun

    Bill Kapaun LawnSite Senior Member
    Posts: 911

    That appears to be the Walbro, which I guess is considered more desirable. According to the IPL, Briggs lists Walbro as the replacement for NIKKI.
    You still have to clean the main Jet.
     

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