WD-45 Carburetor Issue

My 1954 WD-45 tractor runs extremely rough when cold. I know these engines always need a little choke to get warmed up but when I apply any choke it's too rich and kills it. I just can't seem to get it leaned out to run normal. This started when my Dad borrowed the tractor to tow something, put it away and it started leaking gas out of it. He mistakenly turned the L needed in thinking it was the fuel shut off. Ever since then I cannot get it to run properly. Here is a list of everything I have done up to this point:

I've come to the conclusion that it is carburetor icing. After it runs 3-5 minutes and the manifold gets warm it smooths right out and runs with full power. I found some articles describing my exact issue. I'll try it a few times and see how things go. Runs fine in the summer.

Edited by BMinor0788 - 14 Dec 2021 at 8:46am

I was going to use a hair dryer I use for removing stickers to test the theory as well. There's no snow here in western PA so I have no use for the tractor as of now. I will report back when I test.

My 45 has iced up like that during colder weather. I bent up a piece of tin that I stick inside the frame rail, and under the edge of the hood.
 It helps considerably if you never run it above a low idle till it warms up good.

My WD-45 does it at startup. It's fine before it starts. It's just the venturi effect with the cold air + humidity that ices it up until it warms up. Once mine is warm ~ 3-5 minutes idling or just above idle it runs good. This is my first time owning a WD-45 as my CA has never done this so I'm learning. In the summer it runs perfect cold or hot.