Farmall H Not Starting... Spark, Fuel, No Start

Hello Everyone

About ready to start beating my head against a wall...

We bought a 43 Farmall H back in April. It ran fine for a few days then we began having problems. The tractor start and run and shut off after 10-15 seconds each time. I suspected it was the carburetor. Cleaned it out and continued to do the same thing.

Few months went by before we were able to work on it again..it was basically an ornament in the shed.

Since then I've replaced the distributor cap, ignition coil, spark plugs, and spark plug wires. Still nothing. I tested to make sure I was getting spark to the plugs with a spark plug tester and also took one of the plugs out and observed a blue spark. I know I'm getting spark but how do I tell if its a weak spark? I also tried spraying fuel into the spark plug holes, gave it a crank, and it still wouldn't start.

I have fuel coming to the carb but I'm not certain its "misting" out and making it to the cylinder though. I've read on previous post that I could have someone look while the spark plug is removed and I crank the engine. I'll have to do this tomorrow when it's light out.

I plan on ordering a carb rebuild kit since I suspect the float could be bad considering the 10-15 second run time.

Anyway, any help is greatly appreciated. Thank you in advance!!!

-cazarda

Had a 1952 H that turned into hard starter. New wiring
harness and tune up items minimal change. Sold to neighbor.
He took starter off and had it gone through by the shop in
Racine MN. Now it starts first time over. Starter was drawing
too much juice and spark was weak.

How much fuel is coming to the carb ? You should unhook the fuel line and let it run into a can. The flow should be continuous and a
stream the size of a pencil. If you don't have that flow , you only have enough in the carb to start and run for a few seconds and then
starve. You let it sit and the fuel slowly fills the carb , enough to start it again for a few seconds. My vote is a fuel supply issue.
Good luck with it.

Spark needs to be a blue/white in color and jump a 1/4 inch gap or more.
Pull the carb drain plug and you should get a steady flow of gas that will fill a pint jar in less then 3 minutes and 2 is even better

The test may not pick a blocked filter on the intake to the carburetor. All IH letter series tractors have a gauze fuel filter at the carburetor fuel inlet.

I'm leaning towards a gas flow issue.
Sounds like its running long enough to
empty carb bowl, and starves itself
out of gas (very little or no fuel
flow through the carb needle valve).
This can be caused by a plugged up
line someplace, possibly at the screen
at the carb inlet. Or possibly the
needle valve is sticking shut when the
float lowers.
I'd take carb apart, clean, inspect,
and re-assemble. I'd shy away from a
rebuild kit. First off, you don't know
for sure that is your problem. Just a
good guess. Secondly, rebuild kits are
lesser quality than original carb
pieces. You don't want to be replacing
that stuff if its not needed. And
lastly, not much can go wrong in there
other than getting tarred up and what
have.

That is true as for how they came from the factory but over the years many do not have that any more due to getting clogged up and the farm removing them

You're starting to change a lot of stuff without knowing for sure and that often leads to more confusion than when you started. I agree with the other posters to start looking at gas flow first. When you crank
your tractor does gas eventually drip out of the carb. They will do that if you crank a lot and they don't start. You need to find out if you have compression which means you have suction to pull gas into the
cylinders and you need to find out if you have a good gas flow all the time. I've had several problems over the past few years with not only screens plugged up like the guys are saying but also stuff just
plugging the outlet hole in the tank. My H quit a while back and I found a gel like material plugging the outlet that caused the problem. I also just had a problem last week with my H and found the sediment
bowl full of water causing the problem.

Test first, replace second.

If you find that you have spark, replacing the ignition components is a waste of time and money, and introduces more variables into the troubleshooting. New components being bad out of the package is a very real possibility. Installing them incorrectly due to inexperience is a very real possibility. Draw pistol. Chamber round. Aim down. Shoot self in foot.

Most likely you're either getting too much or too little fuel. Remove the fuel line from the carburetor and let it run into a catch can. You should get a strong stream of gasoline out the line for as long as you let it run. If it dribbles and stops you have a blockage. If it runs fine then you need to go back to the carburetor.

If you're new to working on carburetors, you're not going to get it right on the first try.

Take the air cleaner tube off at the carb. Hold your hand over the carb. , hit the starter switch to see if you have good suction at the carb. Could be bad manifold gaskets.

i suspect the float could be bad considering the 10-15 second run time do you know what the float does? if the float is heavy such as
having a pin hole in it the tractor will be flooding and smoking black. , is that what is happening? if it starts and just stops you are
starving for fuel and its not the float. you have clogged up carburator pickup tube. and how did you clean out this carb? i hear this
all the time i cleaned the carb , but did you clean it properly. dont know your mechanical ability's or anything and that is why i ask.
then people think i am being ignorant. give the complete story. are you totally familiar with carb cleaning and installing kits? just want
to know. if you crank it over and have a spray bottle to mist it into the carb intake the tractor WILL RUN.