M/S TSX Carb part 3

Remove the parts from the carburetor cleaner.  While the casting is still wet and using the information documented by GB_ MT and JMOR run a wire through all the passages. I use guitar strings.

I can always get a wire through the top hole shown. I can sometimes get a wire through the lower hole as it does a tight turn. Not shown is the hole to the side which is part of the economizer circuit which I can't always get a wire through either  but will be visible if the casting is turned over and you look in the hole for the economizer jet. Do the same to the lower casting.

Clean the castings using your favorite canned quick drying solvent. Use the front access hole to spray cleaner in each of the holes ensuring the solvent is exiting a different hole. Here the tube is being directed to the economizer circuit. This is another place for safety glasses and gloves.  Follow-up with compressed air directed to all the passages.

Your castings may still have some residue on them. I use a Dremel tool with small wire wheels to clean my castings.

After cleaning your castings, run the wire through all the passages again.  After cleaning and running the wire through the passages, clean them again with compressed solvent and follow-up with compressed air directed to all the passages.

Run a fine mill file lightly across the mating surfaces to remove any burrs only.

Check to see if the castings mate. There are many carbs out there and the halves may have been swapped or the castings could be damaged or warped. While you may be able to double gasket the carb the dimensions for the venturi are dependent on 1 gasket being used.

Using the info provided by GB in MT verify the orifice size on your jets. You can use number drills, or welder tip cleaners with a MIC or any way you can. There are simply too many jets out there to assume yours are correct. I used a set of welder tip cleaners and very smal drill bits finding the ones that fit then mic'd them.

Install the main jet. Use the widest screwdriver that will fit and snug the jet in but don't over tighten. Note the camera has a way of bringing out reds and the casting appears rusted in the photo, it's actually much cleaner in person. Install the plug on the bottom of the carb.

Clean the small holes in the main nozzle. There should be 3. There are other nozzles out there that fit that have different hole arrangements.

Install the nozzle using a gasket under the hex head. (picture from teardown)

Install the throttle shaft seal lips pointing in, install the retainer which is a very light press fit. I always use a new shaft seal. Install the front plug that was used for access to the small holes in the throat.

Check the fuel needle valve. It may be viton (rubber) tipped or just steel. Either is acceptable. Observe the hole in the seat for burrs. Check to see that the needle moves in the seat without burrs or snags.

Install the float valve seat and gasket. Use a screwdriver that fits (modified) and tighten securely. Fuel leaking around this seat can cause other problems.

Install the idle jet




Install the economizer jet.

Install the throttle shaft and butterfly. If you've lost the orientation of the butterfly it's easy to determine. The edges are not machined square  and if you observe how it opens it won't take long to see how it should fit plus the screw holes are slightly off center. I rotate the shaft as I tighten the screws down getting the butterfly to center/seat in the opening.

Install the fuel needle, body gasket,  and float. Check the float height. I use a 1/4" dia drill bit as a gauge. Here the float height is set properly as the float just touches the drill bit. If needed gently bend the float as shown. I set my float parallel to the casting which can be a subject of discussion. I  do this as its shown in the MS service manual

Remove the float and install the venturi. It only fits one way and if you check you will see that one end is larger than the other.  Run the small end through a new body gasket and reinstall the float. Don't forget to verify the float needle valve is still in.

Mate the two halves and install the 4 body screws. I wiggle to 2 castings in an attempt to get them to center over the 4 screws. Just before the 4 screws are tightened I verify that the power jet needle can be installed fully which requires the castings to be aligned. Once checked back it out and fully tighten the 4 screws. A test to check that the float is not binding is to gently turn the carb upside down them back up and listen for the float. You should be able hear it as it hits its travel limits.

Install the power jet needle/spring/gasket  and run it in untill it bottoms out. Back the screw out 1.5 turns. Install the idle mix needle/spring  and run it in untill it bottoms out. Back the screw out .75 turns. Install the fuel strainer and install the completed carb on the tractor. If completed as shown and the tractor is in good general shape it will start on these settings once the fuel bowl receives gas.

Warm the tractor up and adjust as follows:

Adjust the idle mix for smoothest operation. Backing the screw out leans the mix and with a lean mix the tractor will begin to "pop" in the exhaust. Running too rich will produce a somewhat more constant labored "bub-bub-bub" sound.  My idle mix needles are usually adjusted around .5 turns out. Adjust the idle screw (on the throttle shaft) for idle rpm which the manual says is 400 rpm. Unless you have a tractormeter or other gear you will not know where 400 rpm is but its slower than your car. I don't get to worried about the actual RPM and just adjust for a slow smooth idle.

The power jet is checked by quickly opening the throttle. If the tractor stumbles, open (back out) the needle a little more. If the motor responds well but produces a sooty exhaust the mix is too rich and the valve can be run in a little. Only move the needle in 1/8 turn increments and adjusting the power jet can affect the idle jet setting. Backing the needle out enriches the mix.

Adjust the carb then operate the tractor under a load. Only make small adjustments and then run the tractor some more. It may be necessary to complete this sequence 2 or 3 times to dial in the settings.

Click here to download the carburetor cleaning instructions.





The Carb Shack

Started sometime back, Gary (YT Alias GB in MT) saw a need for people who prefer not to work on carbs to have a place to send them for overhaul. The Carb Shack opened and Gary has preformed a number of carburetor overhauls receiving excellent reviews. If you prefer to have Gary work on your carburetor please contact Gary using the information that follows:

Carb Shack CONTACT INFORMATION (the way it works)

Notify Gary that you want your carb overhauled via email or YT Forum
Email Gary so that he has your contact information
Gary will reply with what is needed from you (picture of carb, questions,
$$$, etc)
After receiving info from Gary you will need to tell him Yes or No
Upon receipt of the carb Gary will rebuild it and test on his 2n
Once satisfied with the operation Gary will return your carb for your evaluation on your tractor.
Gary requests feedback on how the carb operates.
Gary retains info on every carb he overhauls.


NOTE: At present,  Gary only overhauls carb's for the 9N,2N,8N Ford tractors!

Gary's craftsmanship is readily apparent in these completed customer carburetors.
Natural finish


Black finish.





Additional Resources

There are a number of helpful tutorials on just about everything including carburetors hosted by the N Tractor Club. Click here for a shortcut to the How-Tos. Click here for a shortcut to the N Club.

Click here for the Marvel Schebler Carburetor service Manual