RE: Hirobo Shuttle Identification - ZX/ZXX or ??
Looks to me like you have a shuttle ZX. It very well could have a few parts from other shuttles. I can’t really tell for sure because I can’t quite make out your clutch assembly.
The second (smaller) tank can be called many things. Hopper Tank, Header Tank or Reserve tank. The main function of this tank is to keep air out of the tank thus keeping a steady stream of fuel going to your carb. As the main tank drains the smaller tank will stay filled because the main tank is always filling it. Because your reserve tank is always full there is no air for the fuel to foam up incase your helicopter is has some vibration. Foamy fuel, air bubbles in your lines are not kind to engines and can shut your engine off and make you enter the fun world of auto rotations unexpectedly. Don’t let all of this talk about a second tank scare you. It is not necessary to fly with one. Lite hovering and forward flights are fine without one. I would recommend it if you are flying aerobatics and 3D
Also the reserve tank has more obvious purposes. One being that you can have longer flights or a “cushion” so that you don’t end up hundreds of feet in the air and have your tank go dry.
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