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Restricted T. O. No. 02-35GC-1 3. Starting. a. Energize starter, and immediately before meshing the starter to the engine, prime engine two strokes to fill the primer lines with fuel. This is not intended as a priming operation, but is to fill primer lines so that priming is effected immediately. b. Mesh the starter to the engine and at the same time prime the engine with three or four strokes of the primer, and return primer to the locked position. CAUTION: While booster pump is operating hold the primer in towards the locked position when not in use as boost pressure may be sufficient to release handle and cause fuel of fuel in primer lines resulting in a flooding condition. c. When the engine starts firing, move the carburetor mixture control to the "Auto-Rich" position. d. During sub-zero weather, if starting difficulty is encountered, move the carburetor mixture control from the "Idle Cut-Off" to the "Auto-Rich" position at the same time the starter is engaged with the engine. If this practice is used it is essential that the mixture control be moved back to the "Idle Cut-Off" position if the engine does not start during the fourth revolution. This procedure will result in overpriming if extreme caution is not used. Normally the engine will start on the second or third revolution. However, if the engine does not start, turn off the ignition switch and pull the engine through by hand with the carburetor throttles in the wide open position to clear the engine of excess fuel. e. If the engine fails to start after a reasonable number of attempts, consult the Handbook of Service Instructions, T. O. No. 02-35GC-2, for possible cause. 4. Warm-up and Ground Test a. General. - The following paragraphs prescribe ground tests which will be performed prior to flight. (1) Any faulty operation or malfunctioning noted during these ground tests will be investigated and the necessary adjustments made prior take-off. (2) Limits of 30 inches mercury manifold pressure and not over 2000 rpm will provide a sufficient range of power and speed in ground operation to adequately check magnetos, spark plugs, propeller controls, etc. (3) If there is any indication of carburetor ice in engines equipped with turbo-superchargers, cooler shutters should be moved toward the "Closed" position sufficiently to preclude its formation. (4) Adjust the oil cooler shutters as required to maintain specified temperature limits. (5) Mixture control will remain in the "Auto-Rich" position for all ground operation. b. Oil Pressure and Temperature Check. (1) The engines will always be warmed up on the ground until proper lubrication and engine operation for the take-off and flight assured. (2) As soon as the engine has started, watch the oil gage for pressure. Of the oil pressure gage does not indicate pressure within one-half minute, shut down the engine and make an investigation. (3) After the oil gage indicates pressure, shift the propeller to take-off setting and run the engine at 600 to 800 rpm until pressure is normal (a value between 30 and 65 pounds per square inch) for this speed. If oil dilution has not been employed this warm-up will be extended for several minutes, after which the rpm may be increased to 1000. (4) During the warm-up period, the engine rpm will not be permitted to exceed one-half of the maximum permissible ground rpm until after the engine maintains, without fluctuations, at least two-thirds of the minimum full power oil pressure specified, and the oil temperature gage shows a definite increase in oil temperature, indicating that oil is circulating properly. When these conditions are obtained, and the mixture and propeller controls are set for take-off, the engine rom may be increased to check for proper functioning of the engine and engine instruments at higher rpm. However, the maximum permissible ground rpm will not be maintained for periods in excess of twenty to thirty seconds. (The maximum permissible ground rpm and manifold pressure will be those specified for "maximum cruising" in section III, except for the turbo-supercharged engines which require setting of "Take-Off" manifold pressure on the ground.) Tightly baffled air-cooled radial engine cylinders quickly reach a cylinder temperature that is beyond the lubricating range of the oil, resulting in the sticking of pistons or rings. Therefore it is desirable to nose the airplane into the wind during warm-up. Engines will be stopped rather than idled for pro-longed periods after warm-up has been accomplished. c. Ignition System Check. (1) Note the loss of revolutions or manifold pressure when switched to one magneto at a time. When-ever an engine is operated on only one magneto, the manifold pressure must not exceed maximum cruising manifold pressure to avoid detonation when firing on only one set of spark plugs. The propeller governors must be set to take-off speed and throttle adjusted to give cruising engine speed or less during the ignition to give cruising engine speed or less during the ignition check. It is important to switch back to "Both" and leave switch in that position until the engine has picked up the loss in rpm resulting from operating on one magneto before testing for loss in rpm on the other magneto. The normal loss in rpm when operating on -4- RESTRICTED
