My crawler appears to be a mix of all three with an engine tagged as an IXA3 and stamped at the deck as an IXB3. The carb is missing. My updraft box had nothing useful, so I found a Marvel Schebler TSX 948 on an M-H tractor and a Zenith #11487A on a Wisconsin generator in a quarry yesterday. Both fit the flanges and I will have no problem with throttle/choke connections. What do you think will work best on mountain terrain and why? Does anyone have an internet location where I can compare jet/venturi sizes amongst the various TSX series carbs? Thanks.
(http://i221.photobucket.com/albums/dd236/arborigine/Oliver%20OC46/tsx_zpsjbroxyzx.jpg)
(http://i221.photobucket.com/albums/dd236/arborigine/Oliver%20OC46/Zenith_zpsy8rfc7ib.jpg)
I would use the M-S if it has adjustable jets. A tractor carb is made to run on varying angles, whereas a generator sits in one spot most of the time. Not that the Zenith wouldn't work, but I'd start with the M-S.
What size was the engine on the Massey tractor? If similar, you should be ok.
There was not much of the Massey Harris left, but the engine was of about the same size. The only internal difference in carbs of the same maker and series is jetting, and i have a CO analyser to read it with. Cconverting it to the specs for the original Oliver carb would get it into the ballpark, and then make adjustments for what we call gas here. I have not identified any other applications for the Zenith yet.
My second tractor when I was a kid was an HG. It came with a MS carburator. I could not get it to run with that carb. I bought a Tillotson Carburator for it and all was good. The MS carb had fixed jets, The Tillotson was adjusable jets. I wish I had never sold that tractor.