2. Inspecting the Ignition-Switch Wires. The wires leading from the ignition switch must be properly connected—one end to the motor body for ground, and the other end to the post on the breaker box of the magneto.
3. Filling the Radiator. Be sure that the water from the radiator fills the cylinder jackets. Pockets of air may remain in the cylinder jackets even though the radiator may appear full. Turn the motor over a few times by hand after filling the radiator, and then add more water if the radiator will take it. The air pockets, if allowed to remain, may cause overheating and develop serious trouble when the motor is running.
4. Filling the Oil Reservoir. Oil is admitted into the crank-case through the breather tube at the rear. It is well to strain all oil put into the crank-case. In filling the oil reservoir be sure to turn the handle on the oil sight-gauge till it is at right angles with the gauge. The oil sight-gauge is on the side of the lower half of the crank-case. Put in about 3 gallons of the best obtainable oil, Mobile B recommended. It is important to remember that the very best oil is none too good.
5. Oiling Exposed Moving Parts. Oil all rocker-arm bearings before each flight. A little oil should be applied where the push rods pass through the stirrup straps.
6. Filling the Gasoline Tanks. Be certain that all connections in the gasoline system are tight.
7. Turning on the Gasoline. Open the cock leading from the gasoline tank to the carburetor.
8. Charging the Cylinders. With the ignition switch OFF, prime the motor by squirting a little gasoline in each exhaust port and then turn the propeller backward two revolutions. Never open the exhaust valve by operating the rocker-arm by hand, as the push-rod is liable to come out of its socket in the cam follower and bend the rocker-arm when the motor turns over.
9. Starting the Motor by Hand. Always retard the spark part way, to prevent back-firing, by pulling forward the wire attached to the breaker box. Failure to so retard the spark in starting may result in serious injury to the operator. Turn on the ignition switch with throttle partly open; give a quick, strong pull down and outward on the starting crank or propeller. As soon as the motor is started advance the spark by releasing the retard wire.
10. Oil Circulation. Let the motor run at low speed for a few minutes in order to establish oil circulation in all bearings. With all parts functioning properly, the throttle may be opened gradually for warming up before flight.