Carb adjustment

[Ronald J. Kellerman]

I just had my carb rebuilt, but need help on adjusting the idle-adjustment needles. When running in the field, it will get a popping noise, followed by black smoke out of the exhaust pipe, and eventuly loose power till it stalls. Also, how far should the fuel metering screw be turned out if at all. Upon checking the plugs after the above conditions occur, the plugs are black or coked up.
Thank you.

 

[BushogPapa]

Well, it would help a LOT to know which tractor you have..!!
The Mail Fuel (Power) ..depending on the tractor and load requirements can be set anywhere from closed, to perhaps open 2 to 2 1/2 turns..
If you have Black Smoke, you are getting too much fuel..either from that being set too far open or the float is letting the carburetor flood..
Earlier JDs sometimes had a problem with Mud-Dauber Nests plugging the air Inlet above the air-cleaner and they would Choke out Black Smoke and act puney...

Ron..

 

[RLA]

Is this M Tractor by any chance??

 

[Tennessee Wayne]

If your tractor is an M, Mt, 40, 420, 430 with the marvel s. carbureator. The L shaped needle on bottom of carb. is the load needle.
Manual says with tractor in neutral, throttle in wide open position, turn the L shaped screw IN until engine sputters,,,then OUT, one or one and half turns will get you close.
Then fine tuning in or out depending on gas, temp. and how hard you are working her. Those are noted for black smoking and fouling plugs, run with the screw IN as much as possible. If it sputters under a hard load, may have to go OUT a little.

 

[Resting Relics 1]

Ron,
I've gotta agree with the guys. The symtoms you describe is way more than a little adjustment. Sounds like the float is set wrong or needle valve is leaking by. Could even have a hole in the float or they failed to clean the bowl vent if this is a Waterloo tractor. Best send the carb back to who rebuilt it and have them try again. Good Luck.
John