8N carbs

[WayneIA]

Two different carburetors on the same 1951 8N tractor. Both perform well, but one labors at idle while the other seems a lot smother a idle. What should I be looking for? Sorry, I don't have the carb numbers.

 

[JMOR]

For what purpose do you use your tractor "at idle"? :? :roll: :roll:

 

[WayneIA]

The questionable carburetor was brought to me from a 2N that has not run in "years". I was verifying my work by checking it on my 8N "thinking" it should run about the same on either carb. By the way the 2N carb runs the best with the air idle screw out about 2 1/2 runs. which is really not the norm. But I guess I won't see the 2N anyway so be it. But that's not me!!!!

 

[Tim PloughNman Daley]

First, if carbs are the later OEM Marvel-Schebler Units they will have a brass MFG DATE CODE ID TAG riveted to the Ping-Pong paddle boss on the lower half of the carb and the M/S name/logo on one half of one or the other bodies or both. Early 'TSX-33' units had that model in cast recessed characters on the boss, no brass tag, until mid-1948, then Borg-Warner changed the units to the brass ID tag system adding the date code to designate the date of unit manufacture as well as carb model number. The model number 'TSX-33' was used on all 9N,2N, and early 8N tractors, and revamped to the new 'TSX-241' unit in early to mid 1948. Early 8Ns could have a TSX-33 carb with the new brass ID tag as well. However, many carbs have been rebuilt using parts from both, another beauty is parts are interchangeable, so getting a top and bottom with name/logos isn't uncommon. If your carb has no ID tag and/or the Marvel-Schebler logo name is missing, chances are you have one of the many aftermarket clones/units or a Zenith model sold today. Add too that M/S made changes to the 241 carb in 48, 49, 50, and 51. The initial TSX-241 carb was revamped with revisions of 'B' and 'C' with an unmarked suffix being the 'A' version. Other changes are the M/S name-logo on the flange side at first, changed to the bottom half, but I have both halves marked on some TSX-241's and suspect somebody just rebuilt a carb out of parts -see PIX. Also, another change was the addition to the extra brass drain plug. Note my TSX-241 from 4 -1950 has no brass plug, nor does the TSX-33 unit, but my TSX-241B from 1951 has the extra drain plug. I surmise the extra drain plug and 'MARVEL-SCHEBLER' name on the flange only was added after April, 1950 as that is when Ford made a lot of new changes to the 8N. So, to say they are the same requires more scrutiny to a trained eye. I'll bet you'll find they are different in more ways than one. It's also important to know that any 'new' aftermarket component purchased today, 99% of the time a Cheena made product, is NOT going to be set correctly out of the box. Don't assume you can pick it up and go with it before checking it out first internally. You say both run fine so why worry? Many fellas have a working unit and also a spare already rebuilt and ready to go in case of an emergency.


OEM MARVEL-SCHEBLER TSX-241-B CARB w/ID TAG:

M/S TSX-241-B, ID '4-51' w/NAME/LOGO ON UPPER HALF OF FLANGE ONLY AND ADDITIONAL BRASS DRAIN PLUG:

OEM MARVEL-SCHEBLER CARBS; TSX-33 & TSX-241:

OEM MARVEL-SCHEBLER TSX-33 CARB:

OEM MARVEL-SCHEBLER TSX-241 CARB, BOTH HALVES MARKED:

Tim *PloughNman* Daley(MI)