[thetractorman91]

When it's at a low idle it runs fine and when it's at a high idle you can tell it revs up and down but when you drive it especially going up a hill or pulling something it is very bad revving up and down so bad that it jerks you any idea what thus could be I adjusted the carb and got it runnIng smooth when it idles but same thing when I start going any idea ?

 

[bertman]

Check for vacume leaks or to lean of mixture.
You can see if its to lean by pulling the choke out slowly till you find the sweet spot. then you know it needs the float lowered or to adjust it richer

 

[gordon1121]

Bertmans right and if the above dosen't work and it idles good and goes to wide open smooth and then starts hammering take the linkage that runs from the carb to the governer loose loosen the lock nut and make it one or two turns longer and see if it helps.

 

[LikesRedTractors]

My Super C surges when at full throttle, slightly, but under a load and at low idle is smooth as silk. When I first brought it home it would spit, hunt, surge, had a misfire about every three revolutions, and was worse with a load. I found loose spark plugs, and a bad gasket at the carb.

 

[John M]

Almost sounds like a gov. problem, like a loose linkage, but I would start with the carb first. Wore points can do it to!

 

[bill z]

Just an idea here because I had a similar problem once. Check the amount of spark to your plugs.

You didn't say what type of tractor or if it is a mag or coil. However, low spark can do the same as you described. Will run fine till load is applied.

Low spark may be the result of stuff fouling the plug or poor connection to the coil. Just check it out.

 

[thetractorman91]

i can pull the choke about half way and it runs like a dream

 

[BigDaveinKY]

That's usually a fuel flow problem. Could be trash in the tank, sediment bowl screen, carb inlet screen,(if yours has one, not all do) or in a passage in the carb itself.
I'm not familiar with the old Farmall carbs, it could be an air mix adjustment if it has such a critter.

 

[thetractorman91]

figured it out my hydraulic pump was leaking fluid into the crankcase and it was way over full got that fixed runs like a charm