Cub Crafters CARBON CUB SS Maintenance Manual page 71

1. GENERAL
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.
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
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 cylinder #3 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.

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.
CC11-160 MAINTENANCE MANUAL
Manual number SSC10020AMM
Date: 12/18/2013