This engine has a pressurized fuel system but is not fuel injected. Looks like the owner got carried away?

It is a very nice engine at a good price though for Helicopters. Will not work for airplanes. There's no propeller drive set up

"YS .61 ST2
The YS .61's main claim to fame is SMOOTH power and a no-fuss needle valve. On a nice spring day you set the needle slightly rich and then fly until winter. (With some stops for fuel, charging, work and other pesky interruptions!) It's a VERY smooth engine. The YS is not very happy with tuned pipes and generally runs best with a good muffler. Besides price and mounting issues, the only downside to the YS is the somewhat complex method in which it gets its strong, smooth power. The unique fuel tank pressurization system has a lot more maintenance points than the "plain old" venturi type carb on other engines. ALL fuel lines must be pristine, and any dirt in the fuel can cause problems with the check valve, regulator ports, diaphragm AND needle. Again, it's a VERY good engine and if you don't mind trading more complexity (and somewhat higher cost) for more consistent needle setting, it's a great choice."