Could be by the time deere got to the 4020 and 4000 they were giving up on gas and focusing on diesel.

My old tractor is gas and it starts and runs each spring ok. Maybe it's becuse it's red not green?

My old tractor is gas and it starts and runs each spring ok. Maybe it's becuse it's red not green?

My old tractor is gas and it starts and runs each spring ok. Maybe it's becuse it's red not green?

Starbrite startron enzime treatment is the best thing I’ve ever seen for gas stuff that sits. Unbelievable actually.

I'm old enough to have grown up using gas tractors built in 50's. Many were replacements for a team of horses, so only pulled 2 to maybe 4 row equipment. Many were only 40 HP or less. A farm likely had a 200 or 300 gallon fuel tank, so one tank fueled the cars, trucks, lawn mower, chain saws and tractor and tractor had to start in winter and not with help of electric block heaters or ether. And wasn't just tractors. Most combines back then also ran on gas. Oliver even made a combine powered by a 318 Chrysler.

So kinda, sorta made sense. But once equipment got larger in the 60's, diesel quickly took over everything, with old gas tractors kept around for utility work.

We are currently restoring a 1963 Allis D15 and it is a piece of work. A flimsy factory 3 point hitch that is not much bigger than some garden tractors today, yet same engine was also put into crawler dosers and bucket crawlers and other industrial tractors. For those that can remember, the engines used by most carnival rides were Allis gas engines. They have a distinctive sound under load.

Biggest problem with most of these old tractors today is lack of use. If they sit, they suffer. Also, I will only use 91 octane ethanol free gas in it, as ethanol in the gas attracts and collects water over time and that sets off all manner of rust. If not going to use it in winter, either keep it empty or keep it full of 91 octane, plus a can or two of Seafoam in it. And every single time I park it for any length of time beyond overnight, will turn off the gas and burn the carb out dry. And keep a can on the exhaust to keep the mud dabbers from getting any ideas on building a home in the muffler.