Checking antistall screw setting

4. Adjust idle speed to 780±50/min by means of idle adjustment screw (4) (see figure on page 7) after loosening locknut. After adjustment, tighten idle adjustment screw locknut.
5. Move idle control and fuel cut-off lever (18) by hand (see figure on page 7) toward cut-off position by 0.5 - 1 mm. The engine should tend to stall or at least speed should drop. If this does not occur, repeat the previous adjustments described at points 1 - 2 - 3 - 4 to obtain a new engine speed that still lies between 780±50 rpm: then repeat test until a positive result is obtained.

Checking antistall screw setting

Accelerate engine to maximum speed, then release accelerator completely: speed should drop steadily to idle level without fluctuations or judder. Otherwise adjust anti-stall screw as follows:

• if deceleration is too slow, unscrew anti-stall adjustment screw (2) by 1/4 turn
• if deceleration is too fast, tighten anti-stall adjustment screw (2) by 1/4 turn.

1. maximum rpm adjustment screw
2. anti-stall adjustment screw.

Adjusting engine top speed

Move accelerator control lever to end of its travel. If maximum speed of 5150 ± 50 rpm is exceeded, adjust maximum speed screw (1) by tightening until engine speed is as specified. Then tighten nut of screw (1) and apply a lead seal.