2QM20 is the marine version of 2TR20.
Hoye has some parts. I see they offer the same bare replacement cylinder head for YM2000, YM2210, and marine 2QM20. But different head gaskets!
WOW, that's the cleanest pixs I've seen on a Yanmar marine motor showing the back end of the engine. Yes, now it's understandable how the marine rear impeller shaft assy can be removed and a clutch used to fit this in a tractor. I had reservations about how well this could be done.
As for the thermostart, it seems to be a universal part for many of the Japan tractors like Mitsubishi-Satoh, Jima, Hinomoto, Isekie and others in that era. It's a really neat device.
Back to the OP's topic at hand, we sure wrangled out the YM2210 as being LOUD, parts are so-so to acquire for some items and not so good for others, takes a little longer to lift the FEL, Hp is much lower that would even limit a brush mower size & brand type, and limited lift capability on the 3PT arms.
For the OP's 5 acres, the YM2310D would be the minimum to consider. I have a post-hole auger. The ability to mount onto the 3PT with a taller tractor indeed helps a whole bunch. The front end weight of the tractor is a must, with added suitcase weights, will allow the 3PT to pull the auger out of the ground and not lift the front end up doing wheelies. So, the YM2210 would be out of the picture there too. Ideally, the YM2820D or YM3110D or YM2610D would work using the post-hole auger.
Here is how the auger rests before backing up and hooking up. No, I didn't come up with this scheme, but did make modifications so it's EZ to load and store.
As for ditch making, no need for a backhoe. I make 2 passes with the Cub Cadet rear tiller for the garden to bust up the soil. Then take the straight blade on the YM2610, offset the right 3PT arm that greatly tilts the blade, angle the blade via it's pin stop, then start cutting. The ditch turns out as nice as the highway dept does. And, if it's a simple French Drain, the tiller does all the work with passes, dirt removal and more passes. I've gone down 3FT with the tiller alone.
