350 - cutting out

[dhermesc]

I am having an issue with my Farmall 350. When ever the governor kicks in with the engine running at 3/4 to WO throttle it starts to cut out like its only hitting on 2 cylinders. After a few seconds it then smooths out. The carb had not been adjusted in years and I tried to set it to run richer but that didn't help and only made it idle rough so I set it back. Good fuel flow. The points and plugs do have some age and I never got around to checking them out.

 

[Wayne in MN]

Sounds like you need a complete tune-up; both ignition & carburetor cleaning.

 

[rustyfarmall]

(quoted from post at 05:27:08 06/09/15) I am having an issue with my Farmall 350. When ever the governor kicks in with the engine running at 3/4 to WO throttle it starts to cut out like its only hitting on 2 cylinders. After a few seconds it then smooths out. The carb had not been adjusted in years and I tried to set it to run richer but that didn't help and only made it idle rough so I set it back. Good fuel flow. The points and plugs do have some age and I never got around to checking them out.

Sounds like you may have been adjusting the wrong screw. The big one down at the bottom, that points straight forward is the correct screw. Turn it out 1 complete turn and see if that helps. Should NOT affect the idle one way or the other.

 

[El Toro]

If that carburetor has a main jet adjusting screw you need to open it. Even my old Wards tractor has that. Hal

 

[Janicholson]

With all respect, the essential ingredient is diagnosis. It is certainly possible that a tuneup would work to fix the issue, but it could also disguise a problem. If adding fuel to the engine when going to full power is cured by the load screw, the tuneup if done as typically assumed, would not fix it. Jim

 

[dhermesc]

I adjusted the main fuel jet - currently it is set rich, when adjusted 1/2 turn it set the tractor too rich and caused it to miss at idle.

 

[Janicholson]

The idle adjustment (rich lean) is separate from the load screw (lower front screw) and the load screw should not affect idle mixture. I would put the load screw about 4.5 turns out from seated (don't screw it in tight, just touch the closed position), then adjust idle for clean running and proper speed 600 or so. This will take 10 minutes of playing with the idle speed screw and the idle mix screw. The idle mix is a air bypass, and lean is out rich is in. IIRC. If it still hesitates, I would replace the plugs first to assure their firing (I do not like Champion). Jim

 

[Andy Martin]

At full load, and full speed, you should see just a hint of black in the exhaust. If it is near dark, under the same conditions you should see a little blue flame out the exhaust. If everything is working well and adjusted right.

 

[dhermesc]

I'll try that - had only tried adjusting the main adjustment screw. However - setting the load screw out 1/2 a turn did seriously affect the tractor at idle (while hot). Years back (actually about 12-13 years ago) the carb was rebuilt and the tractor ran horribly getting way too much fuel to the point of the spark plugs being fuel soaked. The guy who rebuilt the carb said it was "set" and would only need fine tuning - 1/4 turn adjustment at most. After several days of playing with it I finally reset from seated and the tractor ran great. I haven't jacked with it since.

It sat most of the winter with Stabile and Seafoam in the tank and actually started out running fairly well. After about 20 minutes in the hay field running the mower it started the miss thing.

 

[dhermesc]

I may go ahead and do the plugs (and shine up the points) - it has been years since they were replaced.

 

[David G]

It could be ANYTHING, diagnose and change ONE thing at a time.

 

[rhtx55]

I would try fresh gas first, then clean the sediment bowl, replace the fine mesh screen, then the carb jet adjustment.
Once it has been backed out a turn, and it quits missing at high rpm, THEN back the idle stop screw so it will idle as low as possible, then adjust the idle jet screw in & out until it purrs at idle.

 

[dhermesc]

It runs fine at high RPM, when load is added at high RPM it starts to miss/cutout for a few seconds as the governor opens up. It acts as if it isn't getting enough gas as while the governor is adjusting. Once the governor has opened up the engine smooths out again.