Cub Crafters CC11-100 Maintenance Manual page 72

1. GENERAL
The aircraft is equipped with two 12.5 US gallon fuel tanks located within the wings. The total
usable fuel is approximately 12.0 US gallons per tank. The tank is made of aluminum. The fuel
system has a sump and drain located in the bottom right side of the fuselage aft of the door
opening. Some aircraft have an additional sump and drain located on the bottom left side of the
aircraft just aft of the firewall. These should be drained before each flight to test for water and
sediment in the fuel system. The fuel system is a gravity flow system with no separate boost
pump. Fuel drains from the wing tanks through a selector valve and fuel strainer to the
carburetor.
There is an engine fuel primer system that may be used to start the engine, especially in cold
conditions. The fuel primer draws fuel from the strainer by means of a hand-operated pump on
the instrument panel and injects it into three cylinders for starting.
The fuel flows from the tanks into a selector valve that has four positions and is located on the
lower, left side of the cockpit:

Both - The engine is fed by both fuel tanks

Left - Fuel is supplied by the left tank.

Right - Fuel is supplied by the right tank.

Off - Fuel supply to the engine is cut off.
Fuel may flow from one tank to the other when the selector is in either the OFF or the BOTH
position. When parking the aircraft on a slope, leave the selector on either the left or the right
position to prevent cross feeding and possibly overfilling the lower of the two tanks.
The engine may be operated in the Both, Left, or Right positions. However, the Both position is
required for takeoff and landing.
Fuel quantity is determined with two sight gauges located on either side of the cockpit at the
wing root. The ventilation of the tanks is through tubes located on each of the fuel tank caps.
The vented caps should face forward.
Prior to refueling the aircraft, connect the fueling equipment's grounding wire to either of the
wing tie downs or the engine exhaust pipe. This will ensure there is no electrical potential
difference between the aircraft and the fueling equipment and will minimize the risk of electrical
sparks when the aircraft is being refueled.
5.4.10
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CUB CRAFTERS, INC.
CC11-100 MAINTENANCE MANUAL
Manual number SC10000AMM
Date: 04/18/2013