WM, Workshop Manual, K650, K700, K950, K1250, 2001-06, Power ...

3
Fuel system
Fine adjustment of the idling screw (T)
Adjust the idling speed with the adjuster screw (T).
The idling speed should be adjusted after the high and low speed nozzles have been
adjusted.
If it is necessary to adjust the idling screw turn the screw (T) first clockwise until the
cutting disc begins to rotate, and then anti-clockwise until the cutting disc stops rotating.
The idling speed is correctly adjusted when the engine speed (approx. 2,500 rpm) is
stable in all working positions.
Mod. 650/700
L = 1 1/4
H = 7/8
Mod. 950
L = fast / fixed / Fest / fixé
H = fast / fixed / Fest / fixé
Mod. 1250
L = 1 1/4
H = fast / fixed / Fest / fixé
There should be a good margin between the idling speed and the speed at which the
cutting disc begins to rotate.
!
WARNING!
Do not use the machine if the idling speed cannot be adjusted so that the
cutting disc stops rotating.
Correctly adjusted carburettor
A correctly adjusted carburettor implies that the engine accelerates without hesitation
and does not putter at full throttle.
● If the L-nozzle is set too lean it can be difficult to start the engine and will result in
poor acceleration.
● If the H-nozzle is set too lean this will result in reduced power, poor acceleration and/
or engine damage.
● If the L- and H-nozzles are set too rich this will result in acceleration problems or low
working speed.
B
A
Tank air vent
All models
The tank air vent has a great influence on the function of the carburettor. If it is not
working properly then either overpressure or underpressure will develop in the fuel
tank.
Overpressure results in flooding the carburettor.
Underpressure implies a reduction of the fuel flow to the carburettor, or no fuel flow at
all.
The purpose of the tank air vent is to ensure that there is atmospheric pressure in the
fuel tank during all operating conditions.
Mod. 650, 700
The tank air vent consists of a nonreturn valve (A) which opens at a certain pressure
in both directions.
In one end of the valve (the smooth connection) a sintered metal filter (B) is connected
to prevent dirt from penetrating into the fuel tank.
A
B
Mod. 950
The tank vent valve (B) is accessible
when the tank part and crankcase have
been separated. It cannot be repaired
and must be replaced if it is defective.
Remember to clean the small metal filter
(A) in the end of the hose.
Mod. 950
The fuel tank venting is conducted via a
non return valve of the same design as on
the other machine models.
It is accessible when the tank unit and
crankcase are separated.
Remember when servicing to clean the
small metal filter (A) placed in the end of
the hose.
The non return valve (B) cannot be repaired
and must be replaced if it is defective.
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