My H is Cold Natured!

The first 7-8 times this is what was happening. I would hit the starter with the choke on, close the choke and then it would run for about 15-30 and sputter and stop unless I would quickly give it choke and close the choke and then it would run for another cycle of 15-30 seconds.

So once I got through the 8 times, it finally just ran on it's own, however forget even trying to change the RPM's (throttle) because slowing it from 2/3 power would kill it, and I didn't want to raise the throttle because it was a cold engine and I didn't want to hurt it trying to run it hard.

I know that we (Stan and I) fine tuned the motor, but I was still having fuel flow issues. I figured out why, and that is because the in-line fuel filter I put between the fuel bowl and the carb was creating some type of vaccum and it wasn't letting the fuel down to the carb. So I took out the in-line filter and now it gets lots of fuel. But there still seems to be a problem in the delivery of the fuel/ air mixture. What do you guys think?

After 60 years, your tractor might have it's own quirks to starting. The operator's manual spends half a page on starting the tractor.

When it is cool, my H starts best with a couple cranks of full choke, and then ignition on and the choke off. It needs a little choke to make it run smoothly at first. It the summer, it starts without any choke. BTW, the throttle is usually opened about 1/3 of the way vs. 2/3, to start.

If everything is cleaned out now, put an empty can under the carb, pull off the carb bowl plug and make sure gas is running out fast enough that you are afraid it will rapidly drain your tank. Watch it for 30 seconds or so, don't just look for the initial burst of fuel as it empties the carb bowl. If it's not running out well, go back to the sediment bowl/petcock valve, or the carb inlet screen (differentiate by checking flow at inlet to carb also). If it's got plenty of fuel, pull the adjustment screws out and run carb cleaner through those passages. If that still doesn't do it, pull the carb back off, dissasemble it to clean it all out. You can run guitar strings up through all the passages to help, but if unsure bring it to me after you have everything removed and I can set it in the dip tank overnight and then blow the passages out. If you want to check float operation, you can get a large glass or plastic(clear) bowl, just remove the carb bowl (while the carb is still on the manifold) and hold the glass bowl in place under the carb alowing you to watch the float operate and verify that the needle valve is cutting off. You will still need to visually check to make sure the float is not offset and possibly dragging on the side of the carb bowl though. I wouldn't expect it first, but another real possibility is the new plugs are already fouling just due to all the fooling around we've been doing.

I don't remember seeing any fire out the carb inlet? Is it possible that the firing order got out of whack? I remember the plug wires were all long, have you rerouted the wires to shorten them by chance? If so, verify #1 plug wire still comes off the cap at 2:00 position, and follow clockwise rotation around the cap for the firing order.
Hope that helps,
Stan(VA).

1 - Fire out the carb often indicate be an ignition problem. If you haven't already, put in a fresh set of HOT spark plugs (AC C86, Champion D21, or equivalent) Also replace points, cap, rotor and plug wires. Then set the timing per spec (TDC at idle? I forget...).

2 - How old is the gas in the tank? If it's been there all winter, drain it and refill with gas fresh from the pump. Some of the lousy fuel we get today will go bad in only a couple months - will make a carbureted engine extremely difficult to start or to adjust to run well.

3 - Perhaps the high speed circuit in the carburetor is partially plugged. Especially if messing with the screws has little or no effect on running at speed. Might be time to drop the bowl and have a peek inside.

Also all the above presumes the engine has good compression (no valves are leaking, etc).

Good luck! Properly tuned and sparked, an H should start with just a touch of choke. It should then easily pick up a load without any choke after running only a minute or two.

The colder the temperature the less gasoline vaporizes, the less effectively it vaporizes the less thoroughly it mixes with air, thus the less explosive it is under compression. It takes a higher ratio of gasoline to air to start a cold engine than to keep a warmed up engine running. Carbureted gasoline engines need to have the air flow restricted for cold (here cold means anything below operating temperature) starts because of the need for the higher fuel to air ratio.

This is why the choke plate in carburetors was invented. On my M there is a spring loaded “flipper” in the choke that opens up a bit as soon as the engine fires up. This is to prevent a severe overload of fuel and consequent flooding of the engine if the full choke was left on after it was running. This was an important feature when you were hand cranking it. Depending on the engine and carburetor settings it may take several minutes of operation before the engine will operate smoothly with the choke completely open. The colder the weather, the longer you will need to choke the engine.

I have seen others say that H's don't like a lot of choke for starting, maybe so. I can tell you that my M at 80 degrees F will pop right off, with just a quick feather choke and in a few seconds run fine. At -20 F I have to pull the choke and when it fires up, I wait several seconds before I can even begin to open it up or the engine will starve for fuel. As I said earlier, different engines respond differently, but the principals are still the same.

Hope this helps clarify.

You are trying to "make it cold-blooded" and this is what is giving you fits.

On a cold engine, crack the throttle 2/3. DO NOT PULL THAT CHOKE!

Turn on the ignition and hit the starter. It will start and then will probably immediately try to die. At that point, just "feather" the choke a little (on/off two or three times in rapid succession) until the engine evens out.

Hs just don't like that choke very much and flood very easily. They need a lot of air when starting, not fuel.

Allan