Oil & Fuel Ferguson TO20 Tractor Carburetor Problems

Oren · Jul 6, 2016

I am having problems with my TO20 Ferguson tractor sometimes not wanting to run. Yesterday, I did get it started, but you had to keep the choke pulled out in order to keep it running. I checked to make sure it had proper fuel supply, and it did. Then I had my son start the tractor and I "tried" to adjust the carburetor slightly, but that did not do any good either. Since I am not a mechanic, would someone please tell me how to correctly adjust the carburetor - each of the two adjustments - the screw located farther to the rear of the tractor and the larger knob located further to the front of the carburetor or tractor. Thanks in advance for your help.

Jerry/MT · Jul 6, 2016

How about little more info about the problem? "...sometimes not wanting to run..." s not much of a problem description.

The big knob on the fuel bowl of the M-S Carb is the main jet and it should be tuned out 1-1/4 turns but no less than 1 full turn. It controls the fuel air ratio at powers a bit above idle to full power. The Idle speed is set by a screw on the throttle linkage and is near the block. There is an idle air screw on the throttle body that controls the idle mixture. Since it controls air, it works bass ackwards of the main jet; screwing it in enriches the mixture. It should be backed out to about 3/4 turn from closed. When moving the screws to the full closed position, do not reef them down. Just gently close them.

Before you screw around with the carb, make sure that the ignition system is working correctly, i.e. you have a FAT, BLUISH-WHITE SPARK. Many so called "carb problems" are due to poor spark, not carb mixture issues.

BobG_in_VA · Jul 7, 2016

If it "trys" to run with the choke pulled out, your engine is starving for fuel...you can try turning off the fuel at the tank, then un-screw the connection to the carb, before anything else, check the brass screen going into the carb...is is clogged up? Obviously, clean it anyway and then turn on the gas at the tank and make sure you are getting good flow to the carb...if its less than a full run your tank (inside the tank) screen may be clogged as well...once you make sure enough fuel is getting to the carb then adjust as noted below...let us know... BobG in VA