Farmall 100 missing a beat under load

Ok I have had this problem for a long time now and I think I have found it everytime.
tractor runs great under normal conditons flat ground driving and no load. If I put a fast hitch disk on her or haul a traler load of fire wood up the hill out of the river flats (which can be scarey if it stalls) it will miss a beat and then run great and another 10 seconds or so it misses a beat then runs great again and so on.
I am assuming it is a fuel delivery problem and I think it is at the carb. It seems to get a ton of gas to the carb. Could it be the float? what should I look at it? It is almost like it goes dead for a second then takes off running. I thought if it was the ignition it would do it all the time. can anyone help me with the galloping sound and loss of power on this 100 it is getting very very upsetting to have this happen when I really want to work this tractor!

(quoted from post at 05:39:45 07/08/11) Ok I have had this problem for a long time now and I think I have found it everytime.
tractor runs great under normal conditons flat ground driving and no load. If I put a fast hitch disk on her or haul a traler load of fire wood up the hill out of the river flats (which can be scarey if it stalls) it will miss a beat and then run great and another 10 seconds or so it misses a beat then runs great again and so on.
I am assuming it is a fuel delivery problem and I think it is at the carb. It seems to get a ton of gas to the carb. Could it be the float? what should I look at it? It is almost like it goes dead for a second then takes off running. I thought if it was the ignition it would do it all the time. can anyone help me with the galloping sound and loss of power on this 100 it is getting very very upsetting to have this happen when I really want to work this tractor!

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I doubt it is fuel related. Most likely is ignition. Install a set of Autolite 3116 spark plugs and see if that makes the problem go away. Might want to inspect the plug wires also.

Just an idea have you looked in fuel tank? You may have something floating around in the bottom of the tank.

Plug wires.I had the same problem with my superM,did everything to fix the problem-no results.Finally put on new solid core WIRE(not that silicone suppressor crap)-hasnt missed a lick since!With those old low volotage systems,silicone/corbon core just cant transmit enough voltage.Steve

I will try to get new plug wires and plugs for it.
tank looks good I have had tractors with floaties in the gas tank I know its not that or at least as far as I can tell.
Never would have thought it was electrical but will give it a try.
Chad

(quoted from post at 06:56:58 07/08/11) I will try to get new plug wires and plugs for it.
tank looks good I have had tractors with floaties in the gas tank I know its not that or at least as far as I can tell.
Never would have thought it was electrical but will give it a try.
Chad

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I have seen spark plugs that function just fine when the engine is not working hard, but put the pressure on and they will just sort of "blow out" and stop firing.

So it has issues when pulling hard, but not otherwise. Fuel delivery is still a probable cause. There is a screen at the carb inlet, and there could be needle and seat restrictions as well.
be sure the tank cap vent is not clogged. Fuel needs to flow at about a pint a minute for two minutes to be sure of the supply. If it immediately starts to "gallop" when load is applied, I would suspect internal carb issues. if it runs well for 15 seconds or so then starts doing it, I suspect tank and line issues. Jim

I'm all for changing plug wires if the old ones are old/inadequate. Bad plugs, and more so bad plug wires can cause a whole slew of problems that are hard to diagnose.

However, in this case the problem is only when the engine is under load.

You have to ask yourself what's different when the engine is working harder.

To me - that points more to the governor first - carb second.

If it's sparking at no load, even a weak spark SHOULD be ok under load... Again, definitely worth changing plugs and wires if they're old just to be sure.

But under load the engine slows, and the governor opens the carb for more air/fuel to bring it back up to speed.

If that doesn't happen correctly, the engine's going to have trouble.

You've probably check it over, but since you didn't mention it, I figured I'd throw my two cents in about it just to be sure.

Of course, if the governor is working fine, the carb still has to be able to deliver the fuel/air - but sounds to me like you've checked that area out pretty well.

(quoted from post at 21:04:30 07/08/11) However, in this case the problem is only when the engine is under load.

You have to ask yourself what's different when the engine is working harder.

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Big difference is that as the load increases and the throttle plate opens, more fuel/air enters. This pushes the compression pressure up. Higher pressure takes a hotter spark to fire the plug. Thus an engine needing ignition work will idle OK but miss under load.

Common ailment.