Farmall Cub

Yes, removing the main jet is how I usually check fuel flow.

It really sounds to me like an airflow issue. Either air cannot get into the engine (possibly due to a dirty air filter or a nest in the intake) or air cannot get out of the engine possibly due to a plugged up exhaust.
1) Temporarily remove the air filter hose from the carb and see if that helps. Also take a look at the choke to make sure the choke plate is staying open.
2) Poke around the exhaust pipe with a coat hanger bent like a hook and see if you can find something plugging it up.

Be careful because poking around a possible bees nest may require a speedy exit.

I think this may have to be my last post on the forum. I looked inside my fuel tank with a flashlight. It appears pristine. I continued looking as I opened the valve, and I could see the valve stem rotating and screwing back to allow the fuel to flow. All looks as it should be. I removed the main jet and fuel flowed out of the carb. (I wish I actually knew how much should be flowing from that opening, and at what rate.) I removed each spark plug. They were all uniformly black, as if running rich, but did not appear to be oil fouled. I did a compression check and got a range from 118 to 121 lbs, which I think is quite acceptable. I then moved over to the magneto side to check the point gap. As I removed the magneto cap, the #2 plug wire fell off the cap tower!! I secured the plug wire, snapped back on the mag. cap, reinstalled the spark plugs and cranked up the Cub. It ran without dying!! I fear that I shall die from terminal embarrassment. Thanks to all who responded with helpful advice. All though none of you hit the nail on the head, at least I was encourrged to check out the ignition system which eventually resulted in the fix. I will now resign from the Farmall Cub forum. My shame is too great to ever darken these hallowed halls again. I will also be turning in my membership card for the IH Collectors Club.

Stanley:

Don't be silly ..

You have no idea how many of us have done stuff like that, I know cause I have ... not once, not twice but multiple times It is all part of the learning curve. Not just that, and if anyone says they have never done this ... well I wouldn't believe em

Good thing is that you have learned a lot of stuff well and you were the one that finally diagnosed it and got it fixed. and that is the Rest of the Story !

Ditto to what Rudi said. Lots of us have had moments like that. You are unusual because you admitted it.

thiggy; I'm not sure about removing the jet to check flow but I believe that it should give a good indication as to flow. Generally but not always, if you have a lack of fuel problem, when choking it, the engine should run better. At least for a little bit. Although thinking about it, in your case where you can't advance from an idle, maybe not.

Glad you figured it out. I was all set to tell of a similar situation years ago which involved a broken spring in a J4 Mag (I think that's what our local expert called it) on another 1949 cub.

Thiggy, I've done things that make that look like a pure genius act. There are people on this forum who could blackmail me forever if they wanted to. Just to keep them quiet on some of my more brainy stunts.

thiggy wrote: My shame is too great to ever darken these hallowed halls again. I will also be turning in my membership card for the IH Collectors Club.

It's a good thing we didn't show you the secret handshake while you were at DSCF!

I'm not even going to begin to come clean!!!!!!!!!! If you didn't see it, it didn't happen! Vern

I was mowing when when the cub suddenly died, I restarted it, let out the clutch, died. tried it again, died. Started checking to see why I'm not getting fuel, have plenty of gas, have flow, cleaned the main jet. I'm getting back on to try it again when I look down and realized the mowing deck is plowing into the yard! A tree limb had knocked my touch control lever all the way back. I was sure it wasn't getting fuel, when all I had to do look down. Dale.