Model M Carburetor

Cavalier

Member
I have a model M serial number M - 55113. The carb I have on it is a TSX530. I need to replace but will not buy these universal one carb fits all crap again. Been there--done that. Is this the original model carb for this tractor? Or is it possibly TSX245? I bought a rebuilt DLTX34 for my B and it runs great, but I don't think the guy has any M carbs. Any suggestions on where to go to find a reputable rebuilder of the correct carb?

Thanks for your help.
 
Factory parts catalog show two carburetor options, "gasoline" and "all fuel" but doesn't give the TSX-numbers.

What's so bad about it that you are hesitant to simply O.H. it yourself, it's NOT rocket surgery!
 
(quoted from post at 19:09:45 10/17/17) Factory parts catalog show two carburetor options, "gasoline" and "all fuel" but doesn't give the TSX-numbers.

What's so bad about it that you are hesitant to simply O.H. it yourself, it's NOT rocket surgery!
The adjustment needle can be turned all the way in and there is no difference in engine performance. That engine should stall out but does not. Im told internal issue, possibly hairline crack. O/H was performed but problem only evident when engine running and needle closed.
 
Per the manual I have the original carb was a TSX-245 it was superseded with the TSX-530, per the manual that carb has a fixed power jet only adjustable jet is the idle jet
GB in MN
 
"I am really not playing with anything but I am referring to the idle adjustment needle."

NOT sure why we have to tug and pull these little details out of you, posting ALL pertinent info makes it a lot easier for us remote "guessers" to do our job! ;-)

Those MS idle needles operate BACKWARDS, if the needle is screwed in/CW/closed air is cut off from the idle mixture, making it rich. When the needle is screwed OUTWARDS (CCW) more and more additional air is added to the idle circuit 'til the mixture is so lean the engine begins to stumbles, then likely stall if it's screwed out farther.

So if the idle circuit is plugged somewhere the screw will have no effect on idle. Sound familiar?

So the first thing to do is make sure the idle gasoline passages are clear/open from the bottom of the carb (main jet area), up to the body gasket area, (and that the gasket is "good" there) on to the bottom of the idle screw area, and on to the 3 or so little drillings in the throttle bore next to where that side of the throttle plate is when at slow idle position.

How the throttle plate is centered in the bore before the two little screws are tightened can also have an effect here, with smoothness of idle and :transfer to the :load" circuit.

Question, post back, 'til then,check out those areas.

All the being said, the wrong venturi, or a damaged or improperly installed venturi that's not sealing at the body joint can cause some weird idle issues, as well.
 
The origonal M was a TSX245. Your TSX530 came on a 40. It will work fine and is pert near identical to the orig. That carb is quite simple to rebuild and should you have
any issues we will be glad to help. If you don't feel comfortable tackling it poppinjohn /aka/ (Mike Shelby) would be a good choice.

There are three tiny holes in the center of the throat that are tricky to clean out after you remove the idle jet and economizer jet. I use tig tip cleaners for all the holes. You'll need
to grind some screwdrivers to fit the jets and nozzle but everything else is easy as pie. Do order a new sintered bronze weep plug for the bottom from Roberts carb if you
do it yourself. A small pin punch will pop it right out and a larger one will pop the new one back in.

The idle screw (top) is for air so screwing it all the way in and not stalling just means it's pulling air from somewhere. Probably a bad gasket.
 
When I did my first one I was scared to death. Just have to do some question asking on here, do some reading about your carb, assemble the tools and go. Not many moving parts to mess with in there.
 
I will just add that the model 40 carb. works great on my M

My M had a one size fits all zenith replacement on it when I bought it. It ran fine with that too ,but with the extremely tight location to the air cleaner it did not let the hose fit properly for me.
 
thank you for the link... I've always been able to make these Old John Deere Run OK Until the one
I have spent too much time on now!
 
(quoted from post at 22:00:04 10/17/17) "I am really not playing with anything but I am referring to the idle adjustment needle."

NOT sure why we have to tug and pull these little details out of you, posting ALL pertinent info makes it a lot easier for us remote "guessers" to do our job! ;-)

Those MS idle needles operate BACKWARDS, if the needle is screwed in/CW/closed air is cut off from the idle mixture, making it rich. When the needle is screwed OUTWARDS (CCW) more and more additional air is added to the idle circuit 'til the mixture is so lean the engine begins to stumbles, then likely stall if it's screwed out farther.

So if the idle circuit is plugged somewhere the screw will have no effect on idle. Sound familiar?

So the first thing to do is make sure the idle gasoline passages are clear/open from the bottom of the carb (main jet area), up to the body gasket area, (and that the gasket is "good" there) on to the bottom of the idle screw area, and on to the 3 or so little drillings in the throttle bore next to where that side of the throttle plate is when at slow idle position.

How the throttle plate is centered in the bore before the two little screws are tightened can also have an effect here, with smoothness of idle and :transfer to the :load" circuit.

Question, post back, 'til then,check out those areas.

All the being said, the wrong venturi, or a damaged or improperly installed venturi that's not sealing at the body joint can cause some weird idle issues, as well.

Bob, I do thank you for your expert input. I do appreciate it.
 

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