Help adjusting 730D pony

[raklet]

I would appreciate some advice on getting my 730D pony running better than it is. It will not run at all when the lever is in the start position and will only run in the run position with the choke lever about half way (but needs constant adjustment to keep it going).

The pony dies within a few seconds of engaging the flywheel, but on the bright side, the main does fire with those few turns that it gets.

I suspect carburetor adjustment issues and have tried searching for instructions on adjusting it, but I only ever find "follow instructions in the service manual".

I know there are other threads out there that give basic instructions for other models / tractors, but I'm ashamed to admit that I'm young enough to hardly even know what a carburetor is. I need a little hand holding to get started.

Thanks in advance,

Tyler
 

[Blksmok]

Tyler...check to see that you have adequate flow of gasoline coming out of the small tank. Some of those tanks have a small screen filter in the outlet that can become plugged. Remove the elbow fitting and run a phillips head screw driver up the opening. Then make sure you have a good fuel line from the tank to the carburetor. No kinks or sharp bends. Always have the fuel tank topped off before starting the pony engine. If none of these actions solve the problem you'll have to remove the carburetor for a thorough cleaning and float adjustment. Also make sure the gasket between the carb base and the intake manifold is good and not allowing air to be sucked in at that interface. The adjustment needle valve on the front of the carb should be 1 1/2 turns from seating and the high speed needle on the backside of the carb should be 1 1/2 turns from being seated. Both of these are starting points before finer adjustment. The fact that you have to run it on half choke indicates it's got some sort of flow restriction. When you clean the carburetor make sure you clean the small metering orifice in the bottom of the float bowl. There's suppose to be a 1/16 inch opening in that brass part. It's normally plugged from gasoline going bad or white aluminum corrosion particles. Be gentle when disassembling the small carb parts,,,pretty easy to twist/break things.
 

[Rich Duane]

FIT brought up another problem with the new ignition coils not putting out properly a while back. He removed the resistor at the switch and it corrected this problem.
I had the same problem as described above and with the removal of the resistor the pony runs fine.
I believe he said something about the way they wind the new ignition coils.

Rich
 

[raklet]

Thank you. I will make sure to check each of those items as I have not taken the fuel assembly / carburetor apart previous to this.

[buickanddeere]

Something looks odd with item # 34. It's the fuel transfer tube
and is often twisted off and broken when over tightened when
a tinkerer thinks it's a mixture adjustment.
As previously stated about the coil topic. A post coil and
spring clip ignition wire together or a spring clip coil and a post
style wire together don't work well.
 

[raklet]

Let me see if I follow so far.

#34 is non-adjustable. Clean it, install it, don't overtighten.

Only adjustments made are to #1 and #36?

How do I tell whether there are new coils or not? If I remove the resistor wire and direct jump the coils, can I damage them if they are original coils?
 

[MSD]

When I got my 720 #34 was missing from the carb. I found one at
the local Cat dealer. They had the gaskets for it and needle and
seat.
 

[Rich Duane]

I thought you may have changed them but if not I
doubt that the original style are still functioning.
Rich
 

[Blksmok]

Tyler...#34 has a very small hole perpendicular to the tube. It near the front of that part. Make sure it's not plugged. The "original " coils were white and kind of waxy. Replacement coils are usually black. The real shiny ones are foreign made,,the dull black ones are U.S. made..generally. The best way to check your coils is to take a new spare spark plug, detach number 1 plug wire, hook it to your spare plug, ground that plug to the engine, crank the engine and you should have a snappy blue spark. If you have spark on #1 you will also have spark on #3 as both plugs fire off of the same coil. Both plugs need to be grounded to run this test. Repeat this procedure on #2 plug to see if your other coil is good. No spark can be due to bad coils, faulty ignition switch or loose/dirty wire connections.
 

[Blksmok]

Tyler ...the descriptions for 34 and 36 should be reversed. 34 is not adjustable and 36 is.
 

[raklet]

[Blksmok]

Tyler...you need to remove the float bowl assembly to get that broken jet out. Rebuild kits are available from JD. Make sure you have a good phenolic (dark brown) float. There are not a lot of serviceable parts in these cabs. Not sure where you'll find the broken carb jet/tube.
 

[raklet]

Today must be my lucky day. I tried tapping the tube out from either end and it would not budge a bit. I was thinking I would have to go source another complete carb, so on a long shot, I took a small drill bit and started drilling into the center of the idle jet. After a few seconds, the whole thing popped out. The outer tube that it slides into (what is it called, btw?) appears to be okay.

www.robertscarbrepair.com has a repair kit and also appear to have an idle jet available as a separate part. I'll call tomorrow to see what's in stock.