Well, yes. These two pieces are kind of integral to successful work. Besides, the safety measures dictate to use them as well.
If you didn’t know, the automatic voltage regulator or AVR maintains output terminal voltage at the set rate. For example, if the operating temperature changes, AVR will do its best to correct the field current by increasing/decreasing the flow that goes to the exciter stator.
The generator hose allows you to fill up the fuel tank. But remember: if you prefer liquid propane to gasoline, you may need a longer 5-feet hose that can be used with low pressure gas application.