View Full Version : D2 Pony carb question.

03-28-2015, 05:59 PM
Hi Guys. I recently bought a N.O.S. Zenith carb from Ebay hoping it was a direct bolt on for my pony motor.

Just my luck it is different in a couple aspects such as the throttle/choke being controlled from the opposite side of the one I have. If I have to I'll figure out how to modify the linkage to work for that part but something else has me stumped.

On the float bowl my original carb only has a brass fitting for the gas line to hook up to. This one has two fittings. One fitting is directly below the other. Can anyone tell me what the second or lower fitting was meant to be used for?

I have searched for pics of the same carb but cannot find any info on it. It was kind of a crap shoot buying this carb and the limited amount of info I could find didn't really help me to determine if the part was okay for my machine. I now own it so I have to figure out how to use it. Thanks in advance for any help.

Old Magnet
03-28-2015, 06:21 PM
Some of the pony carbs had a second (lower) tap where a vent was connected at the float bowl fill level.

03-28-2015, 07:22 PM
Coleman, send a couple of photos of the carb and the number that is stamped into the round plate riveted to the top of the carb. One number will be something like 5Fxxxx (or similar) and the other will be a five digit number like 10575 (or similar).
Whatever you have will be able to be swapped with someone that has the correct one.

Old Magnet
03-28-2015, 07:31 PM
Actually that's not a bad feature to have. Prevents a stuck float or high fuel level from flooding the engine. The feature was dropped when they went to the drain port passage in the intake runner but the small passage was usually plugged up with crud and didn't work thus engine flooding is quite common if the float valve isn't working correctly.

03-28-2015, 09:24 PM
With the throttle and choke levers being on the wrong side it sounds like you got the Zenith model that was made for the John Deere tractor pony motors, lots of similarities to the Cat ones though, I believe the float bowl is directly interchangeable.

03-28-2015, 10:41 PM
The D4600, 318 d6s used this carb, float bowl are the same, lot of work to change over, same thing with the carb for a D50, RD7 75 RD8, its different than the later D7s D8s which have the throttle control on the inside, Ken

03-29-2015, 08:45 AM
I have a lot of u series d4 and d2 pony carb parts. all used and usable.

03-29-2015, 09:55 AM
The carb still has a tag from the factory on it and came in a Cat box. Also the studs that screw into the top were included in a seperate enveloppe which was also Caterpillar packing so I really don't think it was for a John Deere.

So,is that just an overflow for the float bowl? If so can I just leave it alone and use it as is?

As for the linkage I suppose I can figure something out to deal with that. I will see if I can post some pics of the carb later today. If the weather stays decent I might get out and have a look at the old girl later today.

I really hope I can use that carb without too much trouble as I really want to get her going soon. Thanks again Guys!

03-29-2015, 05:28 PM
Hi Team,
a quick check of my D2, D4 and D6 parts books shows the D6 carb has the control levers on the opposite side to the D2, D4 ones.
My Parts Book for an early D6 4R680-up & 5R903-up shows the Carb P/No is likely to be 7B4727 and Zenith Model No--TU-4C #9549A. Pic shows the elbow and filter carby bowl overflow drain also. Later U series PB does not show the elbow.
Eddie B.