Hey Splat,
The YM240 was a domestic built contract tractor imported from Japan. They had a manufacturing run from 1977-’81 and the 2WD retailed for around $6000. It has the 2 cylinder, 20 PTO, 24 Engine HP diesel. Utilizing the 2TR20(A) (70 C.I. ) engine, one of the strongest smaller engines in the Yanmar lineup. The 2WD model weighs 2000#’s and the 4WD approximately 200 #’s more (or 2200 total). The metric conversion for general specifications show the tractor at 100” long, 46” wide (un-reversed rear wheels) and 69” tall (ground to exhaust tip).
Very fortunately for you, the Authorized Yanmar Dealers may be far and few between, but the YM240D has a sister gray market model, the YM2000D. These tractors, side by side are almost identical and parts support (aftermarket) is excellent.
These tractors have highly over-built transmissions and bull gears as the model was designed for double duty… both the rice farming and dairy industries in Japan.
You should be very pleasantly surprised at how simple, basic and easy routine repairs and upkeep is when performing scheduled maintenance. Service/Parts manuals can be purchase from any 'Authorized Yanmar Dealer' or a host of gray market dealers the sell and service Yanmar tractors.
Turf tires and wheels for your model are expensive and difficult to find (not impossible). The rolling circumference of the tire size in relation to the 4WD is critical, but a good and trustworthy tire/wheel shop should be able to supply the matched combination you need.
Mark