0271 00 6
This procedure provides the best idle characteristics while allowing engine idle speeds in
gear ranging from 750-850 RPM, depending on propeller selection.
Start engine and allow to warm to normal operating temperature. (TM 55-1945-205-10-2)
Shift throttle and shift control lever into forward.
On the engine, verify throttle arm (22) is against idle stop (23).
Verify engine timing pointer (1) is aligned with 4° ATDC (After Top Dead Center) mark on flywheel (2).
Shut down RHIB engine. (TM 55-1945-205-10-2)
Turn idle adjusting screw (28) in or out, as necessary, to correct timing.
Turn idle adjusting screw (28) clockwise to advance timing.
Turn idle adjusting screw (28) counterclockwise to retard timing.
10. Repeat steps 4 through 9.
11. If idle speed is still too high, check induction system for air leaks.
12. If idle speed is too low when engine condition is correct, decrease idle timing to achieve proper RPM
(example: from 6° ATDC to 4° ATDC).
13. If idle speed is inconsistent or the engine runs rough or spits lean, adjust RHIB engine carburetor fuel mixture.
(WP 0317 00)