Farmall H is still running bad

Texaschad25

New User
Ok guys, I'm stumped (and nearly broke). Pulled a 1943 Farmall H home a few months ago after it had sat unused in a neighbors pasture for 10+ years. Here's a list of the things I've done.

Carb rebuilt twice (still drips fuel)
New exhaust intake gasket
New plugs, wires, cap
Adjusted timing
New fluids
Examined manifolds for cracks on intake
Put new temporary plastic fuel tank, hose, filter on
Checked compression-good
Shot some ether around the new manifold gasket-no leaks.
Oil pressure showing 60 pounds with a little blow by.
And probably a few things I missed.
When I crank the tractor, it starts easily with little or no choke. After it cranks, it has a slight pop or occasional backfire (every 4-5 seconds). Tractor has good throttle advance and acceleration. When I hook the 5 foot tandem disk on and start plowing, performance goes downhill fast. If i set the disk at any depth at all, the tractor spits and sputters, backfires and looses all power until I raise the disk up, then it recovers and does fine, with still an occasional slight backfire.
I'm running out of money and sanity fast! What am I missing here guys??
 
It is normal for the carb to drip while choking. The excess fuel simply drips out bottom of carb. Otherwise it shouldn't do that. The float (gas level in carb) is adjustable. Is the float and needle valve filling the carb to full of gas?? You say you adjusted the timing. Why? How do you know it wasn't right to begin with? Maybe you should adjust it back to where it was. One thing I would for sure do is adjust the rocker arm to valve clearances to proper specs. This is seldom done and alot of times can be off considerably after years of use and overlooked. At the same time, make sure none of the valves are sticking which is probly unlikely, but needs to be checked at same time. These are things you can do without spending much money. I'll bet it is something simple like that, don't give up. Worse case scenerio, a burnt valve. But unlikely becuase it should have a constant miss if that was the case.
 
Have you tried a whole new sediment bowl assembly? Come to think of it,you don't have an inline filter in it do you? Bad idea.
This little electric fuel shutoff will take care of the dripping carb problem once and for all.
I dragged another old tractor home the other day,pretty much the same problems. Starves for gas when running,drips from the carb after it sits a while despite cleaning the float. I ordered another one of these electric shutoff for it the other day off Amazon for $26,bought a new sediment bowl assembly yesterday,made up a whole new gas line from the sediment bowl to the carb. Good flow,no leaks.
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What's inside the distributor? Or magneto?

Both have points. Have they been replaced and set?

If it's a distributor, are the bushings tight? Are the advance weights free and springs good?

If the shaft bushings are worn, the points will not stay set, commonly they will change at different RPM, may idle good, then close up of widen out at higher RPM.
 
Sounds like a fuel supply problem. I had this on my JD A would run great idle to WOT with no load. Put the 2 bottom behind it and wouldn't run more than half throttle. I found the sed bowl was plugged inside the tank with a mud dobber nest. Blew it out and yeeeee hawwww it runs like a scalded dog. Before I found this it was on the trailer going to scrap because I was tired of hand starting it !
 
I figured out the problem with the H, and wanted to share it with y'all, even though I'm a little bit embarrassed to relinquish my SIMPLE mistake. Yesterday while visiting my wife's uncle for Easter, I got to looking at his H and determined that I had the #3 and #4 spark plug wires reversed. Got up bright and early this morning, went out and set them to the correct plugs on my H, and now this thing runs like a well oiled machine straight off of the assembly line..... no missing, no backfiring, just good ol' Farmall power. Needless to say, I'm happier than a pig in slop!
Think I'll go out and turn some earth, just for the heck of it. 👍🚜
 

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