I raced motocross on one of the back when they were new. And, I worked at a shop that sponsored a top District 37 Pro Desert racer, some other riders, and the owner of the shop who all rode them. We did some modifications that really made them a much better bike.
1: They had a tendency to bend the 5th gear shift fork and pop out of 5th gear. For a pro desert racer - that would happen after three or four races because they spent so much time at full throttle in 5th gear. For me, as an MXer, I got about three months out of it riding/racing about two times a week. They would trash the fork and round the dogs on two gears. The remedy is to use a shift drum and the fifth gear shift fork from the previous year model. They are interchangeable. It will last much longer. We never had a problem after making that change.
2: They were way too pipey. Other open class bikes of the day had great low end power. The Yamaha 360 was like a 125 on steroids. The problem was that the barrel porting was already too radical to port it for good low-end, there was no flywheel weight, and the carburetor was too small. The remedy was to use a ported 360 enduro barrel, change the CDI ignition to an enduro ignition(for the heavy flywheel) and coil, and put on a 38 Mikuni. With those mods it was a completely different bike. It had way more power, a broad power band, and lots of low-end.
The enduro barrel doesn't look great because the fins are different and don't match the head. The enduro ignition requires and enduro mag cover. And, it looks better if you also change the back clutch actuator/counter sprocket cover. The barrel, ignition, and side covers bolt right on without modification.
A side benefit of the enduro ignition is that it would give you a charging system for running lights if you had a need for them.
The other oddball thing about them was the engine could run backwards. The CDI would work in either direction. It would typically happen when the bike kicked back when starting, or, if you locked up the back brake and then let of the brake just as you were coming to a stop. The enduro ignition would eliminate that. Or, you could file off one side of the CDI pick-up. I don't remember which side, for sure - i think it was the back.

Wow thanks for sharing all that, I'm glad it's in the thread for us to reference. My first reaction is what are your thoughts on the 73 MX360? Same? Different? I ask because 2 days after I bought the RT2 I bought a 73 mx360 running and one evenings work from riding. It's winter here in MT sonI haven't got to ride it much but my initial thoughts are it's a complete animal. I have 2 DT400s and the MX360 is a completely different animal. A 125 2 stroke on steroids nd maybe meth may be a good way to put it haha. I'm not a fan of CDI, both my DTs have DT250 points ignition swaps and I love em. In looking down the road, what stator & flywheel would I wanna look for to do the swap if I ever needed/wanted to? I'll be referring back to this and look back to your feedback!

The RT2 is on eBay with over 600 views and 30 watchers, 2 days left so I'm curious if it sells...

Also curious of any/all knowledge related to these 360 GYT animals.

The bike sold for a fair price to a guy in Texas that's going to fix it up and race it in vintage class so I couldn't be happier. Can put the money into improving my mx360 and have a 74' DT360 motor to work with also. Any feedback in differences between the 73 mx360 and 74 dt360??