DC Carb.

I have a Case DC that I'm looking to pull at some point. It has a defective carb that needs cleaning and a kit at the least. I was wondering if a different bolt on carb might be more effective. Any other options. It currently has a Zenith and the model badge is missing from the carb. Thanks in advance.

Send us a picture of the carb and the year your DC was manufactured.

There are a couple of different versions of the zenith and you will need to know which one to order a kit.

A kit is a lot cheaper than replacing the whole carb!

As a spectator, I am never impressed by tractors that start out fast and die without spinning the tires. Also never impressed by tractors that creep down the track under 2 mph but can spin their tires.

I like DCs. I had 1952 DCs, but did not pull them for reasons mentioned below.

DCs pulling usually embarrass me-- watching them spin out early if there is any aggressive competition with prepared tractors. The embarrassment is typically caused by using the low height, production drawbar and a clevis. Spin a little and the sled chain is horizontal. SAD!!!

Are you intending to compete with aggressive pullers?

If so, first things first--carb much later. Can you get your drawbar right? Need to keep the sled's chain angle "steep" to transfer max weight from sled to tractor?

If your DC has factory hydraulics, a steep chain angle is impossible!!!!! because getting the drawbar high, forward, and a large loop hole for the sled's hook is impossible. Most competitive tractors do not have the DC's restriction to installing an effective drawbar.

DCs without live PTO have some options to replace or modify the rear transmission cover and still keep the PTO. With great difficulty, I put a proper drawbar on a 49 D. Tires were too small to pull effectively.

Second thing--increase your engine's displacement and compression ratio. This will help spin your wheels without killing the engine. 4 inch pistons and a 5505 head is a good start and not expensive.

Third thing----The DCs governor is sluggish. I have used a piano wire on my CC, D, and L rigged to directly actuate the butterfly using the left hand. Learn where 1600 rpm is by ear and ease there as soon as your left hand is free of clutch duty. This allows you to provide full open butterfly at 1600 rpm. Otherwise the DC governor will probably give you max butterfly open at about 800 to 900 rpm. Take the oil out of the air cleaner.

I don't think a bigger carb will help much unless you want to get really wild with the rpm. Then you have valve floating issues. A bigger Carb will move peak torque to a higher rpm but probably not increase max torque very much. Of course, it is torque that spins the wheels.

Click on the link and scroll down to J.I. Case. It list several different carburetors for the D Series.
Carburetor Cross Reference