Page 1 of 2 12 LastLast
Results 1 to 10 of 12
  1. #1
    New Member
    Join Date
    Jun 2012
    Posts
    20
    Location
    bismarck, north dakota
    Tractor
    john deere

    Default pony motor problem....need help

    my 720 diesel pony moor will not stay running unless i keep choking it
    it acts like it is out of gas but it isn't
    any ideas???

  2. #2
    Elite Member
    Join Date
    Jan 2010
    Posts
    2,634
    Location
    Northern, IL
    Tractor
    Branson 2400H

    Default Re: pony motor problem....need help

    Since it runs with the choke on it would sound like there is debris blocking one of the jets in the carburetor. It has been to many years since I worked on one of them so can't remember if you can easily remove the float bowl on that carb to look for debris or not.
    Artificial Intelligence will never overcome natural stupidity.

    Branson 2400H MMM & FEL

    JD 112

    BX1850 gone but not forgotten

  3. #3
    Elite Member
    Join Date
    Apr 2004
    Posts
    2,667
    Location
    East Coast of Lake Huron
    Tractor
    Deere, several

    Default Re: pony motor problem....need help

    Quote Originally Posted by larson1951 View Post
    my 720 diesel pony moor will not stay running unless i keep choking it
    it acts like it is out of gas but it isn't
    any ideas???
    In 55 years the hose from gas tank to valve/carb is crudded full or deteriorated inside. Roberts Carbs sells a complete carb kit and float. Float level maybe low. Another common fault is somebody that didn't read the operator's manual tries to tinker with the mixture screws. They take a slot screwdriver and start torquing on a promising looking Screw head. Problem is they just twisted off the fuel transfer tube. Engine will never run properly until The tube is replaced.

  4. #4
    New Member
    Join Date
    Jun 2012
    Posts
    20
    Location
    bismarck, north dakota
    Tractor
    john deere

    Default Re: pony motor problem....need help

    thank you for the help
    much appreciated

  5. #5
    New Member
    Join Date
    Jan 2013
    Posts
    4
    Location
    sykesville, md
    Tractor
    jd 720D

    Default Re: pony motor problem....need help

    Hey mine has same issue. I just replaced the plugs. My pony starts fine but needs the choke to just barely start the diesel and it dies out like a honey bee after a sting but the diesel usually starts.






    Quote Originally Posted by larson1951 View Post
    thank you for the help
    much appreciated

  6. #6
    New Member
    Join Date
    Jan 2013
    Posts
    4
    Location
    sykesville, md
    Tractor
    jd 720D

    Default Re: pony motor problem....need help

    Larson1951. How did you resolve your issue??
    My next step will be to remove the lower half of the carburetor and look for clogged jets or improper float level. Can we keep in touch with until it is resolved. Incidentally, my plugs were fouled and sort of moist with oil residue, but alas the brand new plugs did not solve the problem,

  7. #7
    New Member
    Join Date
    Jun 2012
    Posts
    20
    Location
    bismarck, north dakota
    Tractor
    john deere

    Default Re: pony motor problem....need help

    -img_1528-jpg-img_1526-jpg-img_1527-jpg
    Quote Originally Posted by larson1951 View Post
    thank you for the help
    much appreciated
    Quote Originally Posted by azhjph View Post
    Hey mine has same issue. I just replaced the plugs. My pony starts fine but needs the choke to just barely start the diesel and it dies out like a honey bee after a sting but the diesel usually starts.
    Quote Originally Posted by azhjph View Post
    Larson1951. How did you resolve your issue??
    My next step will be to remove the lower half of the carburetor and look for clogged jets or improper float level. Can we keep in touch with until it is resolved. Incidentally, my plugs were fouled and sort of moist with oil residue, but alas the brand new plugs did not solve the problem,
    hey thanks for the advice Mr buickanddeere
    i have two 720 diesel pony start motors with similar problem
    since i am in North Dakota and it is january i need to wait a few months as i have not used them in about 6 months
    but when spring comes i will be checking and looking at the screws on the carb
    i will post my finds at that time and post what i see
    back in the late 50's when i was a kid i would have never imagined that we could be talking about this on a computer
    any john deere person is a friend of mine
    thanks again,
    steve

  8. #8
    Elite Member
    Join Date
    Apr 2004
    Posts
    2,667
    Location
    East Coast of Lake Huron
    Tractor
    Deere, several

    Default Re: pony motor problem....need help

    Just to be clear that fuel transfer tube has a slot head and looks like an idle or main adjustment but isn't . It's possible the tube is twisted off just under the slot head.
    The idle and main adjustments require a greasy back handed reach with your finger tips around the aircleaner.

  9. #9
    New Member
    Join Date
    Jan 2013
    Posts
    4
    Location
    sykesville, md
    Tractor
    jd 720D

    Default

    Dear Larson:

    I am taking a liberty to assume your handle begins with your first name,
    I see you have an early and late 720D. How sweet it is. Do they have the same issues?
    My 720d is a hobby tractor. I have the decals in a drawer for Spring.
    I grew up on a 100 acre dairy farm so our tractors were a Ferguson TO-20 and a Massey Ferguson 50.
    Now I work for USDA in Wash. DC. Retiring this year at 71.5 and hope to play with tractors for a lot of years yet.
    I have loved that two cylinder sound since I drove a Model 50 at a county fair in 1955 .
    Jim
    Attached Thumbnails Attached Thumbnails -image-2875085437-jpg   -image-2132321264-jpg   -image-3863557183-jpg   -image-584576066-jpg   -image-2616415724-jpg  


  10. #10
    New Member
    Join Date
    Jun 2012
    Posts
    20
    Location
    bismarck, north dakota
    Tractor
    john deere

    Default Re: pony motor problem....need help

    Quote Originally Posted by azhjph View Post
    Dear Larson:

    I am taking a liberty to assume your handle begins with your first name,
    I see you have an early and late 720D. How sweet it is. Do they have the same issues?
    My 720d is a hobby tractor. I have the decals in a drawer for Spring.
    I grew up on a 100 acre dairy farm so our tractors were a Ferguson TO-20 and a Massey Ferguson 50.
    Now I work for USDA in Wash. DC. Retiring this year at 71.5 and hope to play with tractors for a lot of years yet.
    I have loved that two cylinder sound since I drove a Model 50 at a county fair in 1955 .
    Jim
    hey welcome to the tractor place
    i really like you tractors
    i sure know what you mean about the sound of the 720

Page 1 of 2 12 LastLast

Similar Threads

  1. Pony engine starting motor "magnetic switch"
    By Rftlts in forum John Deere Owning/Operating
    Replies: 0
    Last Post: 05-30-2011, 07:23 PM
  2. Cat D2, D4 pony motor (starting engine) governor
    By 440roadrunner in forum Parts/Repairs
    Replies: 1
    Last Post: 08-09-2009, 08:31 PM
  3. Cat D2, D4 pony motor (starting engine) governor
    By 440roadrunner in forum Parts/Repairs
    Replies: 1
    Last Post: 08-08-2009, 09:11 PM
  4. what is a pony motor?
    By Anonymous Poster in forum General Vintage Tractors
    Replies: 12
    Last Post: 09-10-2002, 04:41 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© 2014 TractorByNet.com. TractorByNet is a registered trademark of IMC Digital Universe, Inc. Other trademarks on this page are the property of their respective owners.