Husqvarna 240RBD manual Maintenance, Carburettor

MAINTENANCE

Carburettor

Your Husqvarna product has been designed and manufactured to specifications that reduce harmful emissions.

After your unit has been run 8-10 tanks of fuel the engine has broken in. To ensure that your unit is at peak performance and producing the least amount of harmful emissions after break in, have your authorized servicing dealer, who has a revolution counter at his disposal, to adjust your carburettor for optimum operating conditions.

!WARNING!

The complete clutch cover with shaft must be fitted before the machine is started, otherwise the clutch can become loose and cause personal injury.

Basic setting

•The carburettor is set to its basic setting when test run at the factory. The basic setting is richer than the optimal setting and should be kept during the machine‘s first working hours. Thereafter the carburettor should be finely adjusted. Fine adjustment should be carried out by a skilled technician.

NOTE! If the cutting attachment rotates/moves while the engine is idling the T-screw should be turned anti-clockwise until the cutting attachment stops.

Rec. idling speed: 2 700 rpm.

Recommended max. speed: See “technical data”.

WARNING!

If the idling speed cannot be adjusted so

! that the cutting attachment stops,

Operation

•The carburettor governs the engine‘s speed via the throttle. Air/fuel is mixed in the carburettor. The air/fuel mixture is adjustable. To take advantage of the engine‘s optimal output the adjustment must be correct.

•The setting of the carburettor means that the engine is adapted to local conditions, for example, the climate, altitude, petrol and the type of 2- stroke oil.

•The carburettor is equipped with three adjustment possibilities:

L = Low speed needle H = High speed needle T = Idle speed adjuster

screw

H L

T

contact your service workshop. Do not

use the machine until it has been

correctly adjusted or repaired.

Fine adjustment

•When the machine has been ”run-in” the carburettor should be finely adjusted. The fine adjustment should be carried out by qualified person. First adjust the L-jet, then the idling screw T and then the H-jet.

Conditions

•Before any adjustments are made the airfilter should be clean and the airfilter cover fitted. Adjusting the carburettor while a dirty airfilter is in use will result in a leaner mixture when the filter is finally cleaned. This can give rise to serious engine damage.

•Carefully turn the L and H needle to the mid point between fully turned in and fully turned out.

•Do not attempt to adjust the needles beyond the stops as damage can occur.

•Now start the machine according to the starting instructions and run it warm for 10 minutes.

NOTE! If the cutting attachment rotates/moves the T screw should be turned anti-clockwise until the cutting attachment stops.

Low speed needle L

Try to find the highest idling

speed, turning the low speed

•The fuel quantity in relation to the air flow permitted by the throttle opening is adjusted using the L and H-needles. Turning the needles clockwise gives a leaner fuel mixture (less fuel) and turning them anti-clockwise gives a richer fuel mixture (more fuel). A leaner mixture gives high revs while a richer mixture give less revs.

•The T-screw regulates the position of the throttle while the engine is idling. Turning the screw clockwise gives a higher idling speed while turning it anti-clockwise gives a lower idling speed.

needle L clockwise
respectively counter-
clockwise. When the highest
speed has been found, turn
the low speed needle L 1/4
turn counter-clockwise.
NOTE! If the cutting	+ 1/4
attachment rotates/moves in
the idling position, turn the
idling speed screw T
counter-clockwise until the
cutting attachment stops.
	L

English – 19