Farmall 100 - hard to start; easy to pull off. running rough

Hello, friends. Thank you for taking the time to review my post. I should start by saying that - regardless of the years my Daddy has spent patiently trying to teach me - I have
very little comprehension of how these gas burners work. That being said, if anything in this post is unclear or just plum makes no sense, please don't hesitate to point it out
so I can correct it.

What I am looking for: your advice on how to solve an issue with our gardening tractor; a little Farmall 100.
The problem: tractor typically won't start with the hand crank (which we'll be using until we get around to replacing the starter). The tractor cranks right up as soon as we
pull it off. Runs a bit rough once in operation.

What we think we've ruled out as causes:
-fuel is clean
-points and plugs are good
-took the carburetor apart & cleaned thoroughly (as much as possible without carb. rebuild kit, but it should be good)
-cleaned fuel line
-new coil
-float should be set close enough to accurate that it isn't a problem
-oil is good, maintains good level, & not burning oil

A few things we've noticed:
-gas is dripping out of weep hole
-tractor runs rough (especially under a load)
-haven't checked valves yet

Daddy thinks that the engine isn't pulling fuel as strong as it should be, but we can't figure out why. Suspects valves need to be adjusted, but we haven't gotten that far yet.

What are your thoughts? Thank you!
 
What do you mean by "pulling it off"? Do you mean towing it to start? Gas leaking from the carburetor is usually due to flooding the engine, that is too much choke.
Is this a distributor ignition, I suspect, or magneto ignition?
Please post those answers and we will go further.

Dave
 
Respectfully, if you admittedly don't know much, how do you know that any of what you checked is good? I'm not saying this in a mean and snarky way. I am saying this in the name of good common sense. There is nothing wrong with not knowing. It's an opportunity to learn, as long as you're willing. What is wrong is deeming things "good" when you don't really know.

Fuel running out of the weep hole is a clear indication that something is not right with the carburetor. Your float setting is too high, or the needle is leaking. Either way, the float needle is not closing off fuel flow from the tank.

Your Farmall 100 almost 100% has a battery ignition, which can be difficult to start with the hand crank. A good magneto would produce a much hotter spark, making hand cranking easier. I do NOT recommend converting to a magneto, though. That will be more expensive than replacing the starter. New starters can be purchased for <$100.
 
Rough running could be a lot of things though I would start with firing order to make sure the wires are on correctly. Check distributor rotation then put wires on in the correct firing order. Should be on the side of the engine. 1 being closest to the front/radiator. Check the battery is up on charge if not charge it. Then with crank a good spark jumping a 1/4 inch blue white spark. If not fix, gap, on points,condenser, or poor connection in wiring. Dripping is it doing this right after trying to star might be lack of suction at intake hold hand over carb intake and see if it will suck on your hand if not then find out why low compression, not turning fast enough, stuck valves,leaks at intake manifold.
Rough running could also be the valves to tight or loose though usually to tight more than loose. Bad seats or valves, bad plugs,weak spark,worn governor, out of time some. Lots of things to check on. May even be a lack of fuel delivery. Check fuel flow from tank then at carb then out bottom of carb. If it will not fill a pint jar quickly start there and work till it does at the bottom of carb.
 
In addition to things the other guys have said I have a couple of things to add. Make sure timing is OK. I've found on my F14 a hotter plug starts easier - if your plugs are what was originally called for in the manual then step them up to the next range. Last thing on running rough - does it run better with some choke. If it runs better does it now smoke when it wasn't before. Those old farmalls will drip gas from the carb after cranking and no start. It should stop after a moment if the carb itself isn't causing the leak.
 
The engine may suffer from low compression which could be the rings or valves leaking. Put your hand over the air intake on the carburetor and have someone crank the tractor to see how much vacuum you have to pull the fuel/air mixture into the engine. Might want to do a compression test.
 
all I am going to say is it does not take new parts to make an engine run smooth and start easy? if you don't have things adjusted to the factory settings and spec's how will it run smooth? this includes compression check, valve adjustment, points set, timing set, carb set, for the optimum engine performance after you know the compression and spark and gas department is good.
 

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