pony motor problem....need help

[larson1951]

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???

[oldnslo]

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.

[buickanddeere]

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.

[larson1951]

thank you for the help
much appreciated

[azhjph]

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.

thank you for the help
much appreciated

[azhjph]

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,

[larson1951]

thank you for the help
much appreciated

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.

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

[buickanddeere]

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.

[azhjph]

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

[larson1951]

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