9N

Could it be fuel?

Gov'ner seem to be working?

Soundguy

plug wires?

Your description of ..... ..."What causes the tractor to cut out and want to die when a load is placed on it and runs fine without a load. I adjusted the main jet screw with no help. Just rebuilt carb six months ago" ..... .is so BROAD, ya can drive a semi-thru it..... ..but IT AIN'CHUR CARB.

When you place a load on yer tractor, the engine slows down and the GOVERNOR kicks the throttle up to take the load. UNDERSTAND??? So yer problem could be yer governor. With engine runnin' about 1/3 throttle, GRAB-IT with yer dainty little pinkies and try got goose ye carb-governor rod. (it ain't gonna bite you) Does it FIGHT you for increasing engine rpms???

But then yer cuttin' out and dyin' could be weak sparkies. See iff'n they'll jump a 3/16in gap with blue-snott authority. Thats either yer squarecan ignition coil or yer weaksister ignition switch. (you know the one with the key?)

Check yer 4-nipple firing order. 1,2,4,3 CCW. These N-Engines are soooo goood they'll run and sound fine on just 2-sparkies. Usually sparkies 3&4 gitt swapped. Check'em-out. 1,2,4,3 CCW understand?

Then theres the old standby, slipped ignition points (gap = 0.015). You do know itza 15-min job to do the points on the kitchen table, don't you?..... ...Dell, yer self-appointed sparkie-meister

It has a petronix electronic ignition so it ain't the points..... how could sparkies only fail under load?..... How hard is it to replace a governor? and what does the governor run off of..... .....looked but couldn't figure it out.....like I said it runs wide open without a load..... .soon as you put the drag down and put a real good load on it..... ..it immediately starts running slower and then after 30 or 40 feet its sputters and wants to die..... .Bob thinks its a filter..... ...you always think its a key switch.....

Of note it was running fine for months after I rebuilt the carb and put in a new can coil.....just started to happen the last two times I ran it..... .

See? I told you guys, I flunked mind reading. You didn't tell us about your electronic ignition, did you? Weak sparkies can also be caused by failing electronic ignition (or points) as well as by BAD ignition switch. ($10, cheap) Why is it so hard for you to understand that?

You ask..... ."how could sparkies only fail under load?"..... ..'cuz that is one of the failure modes of weak sparkies, HOT-RODDERS and racecar drivers know it well.

So how hard is it to check the 3-filters???

You write..... "How hard is it to replace a governor? and what does the governor run off of?"..... ..the governor runs off 4-balls held between 2-races that are spring-loaded together (except for the balls being in the way) The balls gitt flatspots and races gitt grooved preventing the governor from working. Basic governor kit $50, rebuilt governor $250. Your choice. Gitt out yer I&T FO-4 maintenance manual..... ...respectfully, Dell

Dell you said its easy to check the govenor..... how does one doe that without taking it apart?

GRAB WHAT?..... ... and "try got goose ye carb-governor rod." what the hell does that mean? excuse my ignorance..... ...

And all you have to do is to grab yer throttle rod with yer dainty little pinkies and "JAZZ" or "goose" the carb. (tip: the throttle rod only moves EAZILY in one-direction, and that is the direction to "jazz" or "goose") And iff'n the governor is working correctly, it will "FIGHT" you.

Waddda concept. You can actually touch things and make'm work..... ...respectfully, Dell

But I have to ask the dreaded question: to the best of your knowledge has this tractor ever been overheated?

If not, read on. If so, please tell us.

Check that governor. It is easily done without dismantling anything.

Check the fuel flow. You should see a steady stream of fuel come out of the line.

If the fuel flow and governor look good, and the engine operation returns to normal EVERY TIME the load is removed and AS SOON as the load is removed, your problem is far more likely to be bad spark or compression (gasp!) than a carb problem.

But the BEST way to eliminate the carb is to find a good running tractor similar to yours and borrow the carb to sub it out.

About that ignition: the air-cooled Volkswagen community is the largest group of Petronix (sp?) users out there and they are SHARPLY divided over the reliability of them.

So, replace that ignition switch first. You can also try checking the plugs for correct type and gap.

(In my own personal experience the most common cause of missing under load and only under load is bad or incorrectly gapped plugs. But on the N series it seems to be the ignition switch.)

Then, if all else fails, try subbing out the ignition.

Unless the engine has been overheated. Then the odds shift away from spark and gas towards...