MAINTENANCE
Carburetor
The carburetor has been carefully preset at the fac- tory. However, additional adjustment may be required due to climate, altitude, gasoline and type of two- stroke engine oil used. The instructions below describe how carburetor adjustment should be carried out.
Basic (factory) settings
The carburetor is preset to the basic settings when the blower is tested at the factory. These basic settings are the following:
The H screw has been turned counterclockwise to its end position against the stop.
The L screw has been turned counterclockwise to its end position against the stop.
The carburetor governs the engine speed via the throttle. Air and fuel are mixed in the carburetor. The air/fuel mixture is adjustable. To utilize the blower’s maximum output, the settings must be correct.
The carburetor has three means of adjustment:
H = High speed jet
L = Low speed jet
T = Adjustment screw for idling
H L T
Function
The fuel quantity required in relation to the air flow, provided by the opening in the throttle, is adjusted by the L and H jets. If they are screwed clockwise, the air/fuel mixture becomes leaner (less fuel) and if they are screwed counterclockwise, the mixture becomes richer (more fuel). A leaner mixture gives rise to a higher engine speed and a richer mixture gives rise to a lower engine speed.
The T screw regulates the idling speed. Turning the T screw clockwise will increase the idling speed; turning it counterclockwise will lower the idling speed.
The recommended idling speed is 3000 rpm.
Adjustment
NOTE!
Do not remove the stops in the H and L jets. If these stops are removed, the blower will no longer satisfy the environmental requirements established by the California Air Resources Board.
Low speed jet, L
1.Check that the blower tube (15) and the nozzle (14) are mounted on the blower.
2.Turn the H and L adjustment screws fully counter- clockwise so that they rest against the stop.
3.Start the blower engine, see page 13, and alternate letting it run at idling speed and at half throttle for
4.Set the T screw to the setting, at which the engine runs precisely at idling speed, but not faster.
5.Make a fine adjustment, turning the L screw so that the engine will run at max. idling speed. Then turn the L screw max 1/4 of a turn counterclockwise.
6.Then turn the T screw to increase the engine speed, if necessary.
NOTE!
When setting the H jet, the max. permissible
High speed jet, H
1.Start the blower as described on page 13 and alternate letting it run at idling speed and at half throttle for
2.Give the engine full throttle and adjust the H screw until the engine runs at maximum speed.
3.Turn the H screw 1/8 of a turn counterclockwise (less than 1/8 of a turn if the stop restricts this adjustment).
20 – English
