1951 Baird Beaver's "New" Carburetor

Yeah, the quotes on the word "new" means it's not a new carburetor, but it's new to me. The carburetor that came on this tractor is a Stromberg UR-3/4, which in and of itself is something a little unique. Someone on the Baird Beaver forum took one look at a photo of it and said it was probably from the late 20's/early 30's. Wow, a 90-year-old carburetor. Here's a photo of the Stromberg. If you'll note the air intake of the Stromberg, it is facing directly at the muffler, so an air cleaner won't even fit on it. This carburetor also has a small intake manifold between it and the engine block, which isn't a stock piece for the Wisconsin AKN engine on a Beaver.

1936 John Deere BO Welding Fuel Cap Shields

The B "Orchard" tractor came from the factory with small shields for the air intake and the two fuel caps on the hood, so low-hanging tree branches had less of an opportunity to snag on stuff. My tractor's hood had the air intake shield but the two fuel cap shields were not on the hood, which doesn't make much sense, as the BO hood always had all three shields and the BR hood always had none. Fortunately two proper shields came with the tractor.

Today would be the day I either ruin the hood or come away with a finished product that looks somewhat decent. This first photo below shows the shields. They look like small air inlet scoops but the openings will be facing rearward. The openings are a little dented up so the first job is to try and straighten them.

John Deere LA and BO Repairs

My 1941 JD LA has a battery but the only thing it is hooked to is the starter. Well, and the generator, but I'll get to that. The engine has a magneto so if I had a hand crank, I could start and run the tractor without a battery. The tractor did come from the factory with lights but the front one is currently missing and the rear one is not hooked up. The ammeter is also not hooked up, so yesterday (8/7) I remedied that. I wired up everything and installed a light switch. But it's not any ordinary light switch. Oh no no no no no. Let me explain.

Old tractors like this LA have a very rudimentary charging system. The generator has what's called a cut-out relay (not a voltage regulator), and its only job is to cut any voltage draw from the battery when the generator isn't charging, such as when the engine stops or the generator dies. Since the generator has the ability to put out 10 to 15 amps of current, with no regulator in the system it would boil a battery in short order if the engine ran, say, all day long.

Tractor manufacturers minimized excess current going to the battery by means of a resistor in the generator's field circuit, to lower output of the generator, and they decided to put the resistor on the light switch and they gave control of the resistor to the tractor operator. My LA's generator didn't have a light switch, and happened to be wired for full generator output all the time. Fortunately the engine doesn't run very well, so I think the battery isn't ruined....

The light switch has positions 1, 2, and 3. At the "1" position, the resistor is in the circuit so the generator puts out low current, maybe 4 or 5 amps. The "2" position takes the resistor out of the circuit so the generator puts out full power, maybe 10 to 15 amps. You'd use this if you were just running the tractor for a short time, so the battery could get recharged quickly. The "3" position turns the lights on, so whenever the lights are on, the generator is still putting out full power but some of it is powering the lights so the battery doesn't get full power..

Manufacturers in the mid- to latter-40s I believe started putting voltage regulators on tractors so the output from the generator was automated and more regulated than a system with only a cut-out relay and manually switched resistor.

I recently bought a resistor/light switch and installed it. This first photo is the switch I bought. The resistor sits on the top of the switch (white porcelain cylinder with resistor inside). There's also a fuse on the bottom to protect the light wiring.