Carburetor question on a Case 480CK

TractorSmith · Dec 8, 2009

I just rebuilt the carburetor on my Case 480CK. It runs better, but the problem still exists. It only runs well if the choke is about half closed.
I think I might have stumbled on the problem. I just noticed that the carb is supposed to be a Marvel-Schebler TSX-936, but the tag says it is a TSX-864. Is there a jet I can change to convert it, or do I need a different carb? Any help would sure be appreciated.

Ole Shovel · Dec 9, 2009

480 could have used TSX-936 or TSX-936SL (electric solenoid load needle) or Zenith 14544. No such thing as a TSX-864 but there was a TSX-854 that was for Case 600 so too carb would change it.

mEl · Dec 9, 2009

If that carb fits it should be able to be cleaned and adjusted to work properly. The carb jetting is set so it will give the proper fuel to air mix for the size of the venturi. As I see it a good cleaning and proper adjustment should do the trick. Carbs are not rocket science and there are "universal carbs" that the same carb fits many makes and models with universal throttle and choke shafts that can be adjusted to the application. BTW for what it is worth, that Marvel carb style is my very favorite. mEl

TractorSmith · Dec 9, 2009

Thanks for the replies. Shovel, the tag on this carb definitely says TSX-864 and also has 78J stamped on it. I'm assuming someone has replaced the carb at some point. I did clean it good - soaked in carb cleaner for four days - so I'm sure it's clean. I installed a new kit I bought from Case dealer including gaskets, needle & seat, and throttle shaft seal. Its just like a new one so I was hoping for good results. But, like I said, it runs good until you open the choke, even when its fully warmed up. I've tried going to the extreme both ways with the adjustment screws. When you push the choke in it starts sputtering and dies. I'm just wondering if this is the wrong size carb, can I correct it or if I need to find a TSX-936.

mEl · Dec 9, 2009

How many adjustment screws are there in the carbuerator body? Is there an electric shutoff on the carb sticking up at an anglenear the fuel inlet pipe? Unless it is a fixed jet carb it will have an idle screw located near the bolt flange where the carb bolts on and on most tsx series there is a high speed adjustment that sticks up on an angle out the top of the carb, I have seen some variations that have an adjustment on the bottom at an angle. It needs more high speed fuel but there is NO reason if all is well that it should not run. Can you post a picture of the carb? That would be an enormous help? If you think that you must replace it , send it to me, I'll be glad to take it off your hands but would sooner see it working for you!!!! Thanks, mEl . One more edit to give you something to look at and check. I have seen at least one "rebuild" that the person doing the work forgot to put the venturi in and it would act similar to what you describe, is that a possibility?

TractorSmith · Dec 10, 2009

mEI, it has two adj. screws - the low speed and the high speed at an angle off the top rear like you describe. No electric solenoid. Yes, it does have the venturi in place :wink: . I know because I remember checking to make sure it couldn't be installed upside down.
Sorry, I can't post a picture right now because the tractor is at my mom's place 1 1/2 hrs away. I hope to get there and work on it within the next week or two.
I'll keep you in mind if I do need to replace it. Thanks again.

mEl · Dec 10, 2009

TS, for some reason the high speed circuit is not allowing enough fuel from the bowl to get to the discharge nozzle (the angled nozzle that sticks out in the airstream). I would open up the main adjusting needle seat in the bottom of the bowl a couple drill sizes, Drill from the top side only, you can't hurt doing that as the needle will always adjust it back down. Also, I would remove the discharge nozzle and look clear down in the bottom of that bore and see if there is a jet in there, if so remove it and I mean for good!. Before you take a screwdriver to it take an appropriate sized flat punch and tap the jet a few timews to help loosen it up. Once you study that carb a bit you will see what you have to do to get fuel through it. I have used that carb with homemade venturi to carbureate engines well over 400 CID and it will do what you want it to do, guaranteed. Keep with me on this and we will get you going. With both the main adjusting needle seat and the discharge needle out you should have a good open passage for fuel to flow if that jet is not there. mEl

Carburetor question on a Case 480CK

TractorSmith

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Ole Shovel

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mEl

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TractorSmith

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mEl

Well-known Member

TractorSmith

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mEl

Well-known Member

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