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a heat source, such as an exhaust manifold, before it enters the carburetor. [ Figure 4-23 ] Refer to the RFM (see Chapter 5, Rotorcraft Flight Manual) for the specific procedure as to when and how to apply carburetor heat. 

## Fuel Injection 

In a fuel injection system, fuel and air are metered at the fuel control unit but are not mixed. The fuel is injected directly into the intake port of the cylinder where it is mixed with 

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