840 carb question

[xicor37]

The old MS carb on my 840 (172 engine) has been rebuilt one too many times and it won't hold a tune anymore. I've been looking around trying to find a new one and every place I see only sells a Zenith carb for it. Are these really better as they claim? Secondly; can one of you fine gentlemen provide me a link to the exact carb I need from the best place to purchase one of them? There seems to be a vast amount of questionable sites with them for sale and it's hard to know which one to trust.

Thanks,
~Tyler

 

[Larry Lofton]

I say up front that I’m no expert but my brother put a new Zenith on his 851 and I couldn’t tell that it ran any better. You might want to check out this site, they sell new Zenith and rebuilt MS. I think this site can be trusted; I have purchase a lot of parts from them and have been well please.
Best of luck ….Larry

 

[old]

Never found a carb yet that could not be rebuilt unless it was in fact broken some place. That said nnalert sells true M/S rebuilt carbs that will fit your machine they are not cheap but then neither are the zeniths 800 is toll free 828 is the prefix and the rest is 3276

 

[souNdguy]

IMHO.. a zenith and MS carb will both run the tractor good. the zenith will be more fuel hungry.

I have a zenith on my 850.. it works.. I prefer MS carbs though..

easier to rebuild IMHO..

soundguy

 

[xicor37]

I'm guessing, to get the right rebuild kit I would need to know exactly what carb I have? Where do I find the numbers on it? While it's on the tractor all I can see is the MS marks in the casting. Is the part number on the other side? Also are the places posted earlier still the best places to get a complete rebuild kit with everything including jets, needles, etc.?

Any basic tips on rebuilding a carb? I have never rebuilt a carb. I am quite proficient with engine and electrical work but being an EE and of the young'n variety I am much more familiar and comfortable with fuel injection. As a matter of fact I have only ever owned two vehicles with a carb. A '79 CJ7 and a '77 Silverado.
I could build and program a FI system from scratch but know little of carbs. Never been a better time to learn though. So I guess I'll give it go!

Thanks again,
~Tyler

 

[DollarBill]

I'm guessing, to get the right rebuild kit I would need to know exactly what carb I have? Where do I find the numbers on it?

Tyler, your tractor was originally equipped with a M/S TSX593. The model identification number was on a stamped aluminum tag held onto the carb by a float bowl screw - It was probably tossed during a previous rebuild.

Here's a link to download the service manual for that model carb: MS Service Manual