5-TILLOTSON HW-31A CARBURETTOR ADJUSTEMENT
LEAN 1 T.O.
*
RICHE
¾ T.O. 1 ¼ T.O.
*
T.O. = TURNS OPEN 1 ½ T.O.
Normally the correct setting of the mixture screws, after engine run-in, is the following:
L (close the screw completely and then open): 1 T.O. + ¼ (1 turn and 15’)
H (close the screw completely and then open): ¾ T.O. (45’)
Based on various factors as altitude, ambient temperature etc. It might be
necessary to reset the carburettor to optimize the performance of the engine.
ATTENTION:
- Never lean too much as lean mixture will overheat engine and cause seizure.
- Do not force H or L closed. It may damage the precision machined orifice and render
the carb. unserviceable.
- The adjustment of screw must be performed with warm engine.
( H ) HIGH SPEED FUEL
MIXTURE
REGIM
I
( L ) LOW SPEED FUEL
MIXTUREREGIMI
( I )
TROTTLE
SPEED SCREW