2007 BMW MOTORRAD G 650 XCHALLENGE compression ratio

Turn pneumatic-pump hose3
toward the pneumatic pump
and close velcro fastener2.
Sit on the motorcycle, hold it
upright and allow as much of
your weight as possible to rest
on the motorcycle.
Push in the valve pin, allow air
to escape from the Air Damp-
ing System and check the
level.
You can use the point of
the valve cap to push in the
valve pin.Continue to allow air to escape
until the fore-and-aft tilt indicat-
or shows horizontal.
Screw the valve cap onto the
Air Damping System valve.
Remove the seat ( 41)
Install the pneumatic pump
( 34)
DampingAdjustment for front
suspensionYou can fine-tune the suspension
to the road surface by adjusting
both the compression-stage and
rebound-stage damping charac-teristics of the telescopic forks.
The rebound-stage setting con-
trols the way the suspension re-
acts as it extends, whereas the
compression-stage setting influ-
ences compression of the front
forks under load.
The harder the setting, the more
the movement that the forks can
make to absorb surface irreg-
ularities is damped. When you
choose a soft setting the forks
respond all the more rapidly to
surface irregularities.
Adjusting rebound stage
for front wheelMake sure the ground is level
and firm and place the motor-
cycle on its stand.
438zOperation

You adjust the rebound-stage
characteristic by turning adjust-
ing screw1.
If you want harder damping,
use a screwdriver to turn theadjusting screw in the+direc-
tion.
If you want softer damping, use
a screwdriver to turn the ad-
justing screw in the - direction.
Rebound stage, basic
setting, front
Turn adjusting screw as far
as it will go in the "+" dir-
ection, then back it off 11
clicks in the "-" direction.
Adjusting compression
stage for front wheelAdjust the compression stage
by turning adjusting screw1.
If you want harder damping,
use a screwdriver to turn the
439zOperation

adjusting screw in the+direc-
tion.
If you want softer damping, use
a screwdriver to turn the ad-
justing screw in the - direction.
Compression stage, basic
setting, front
Turn adjusting screw as far
as it will go in the "+" dir-
ection, then back it off 11
clicks in the "-" direction.Adjustment for rear
suspensionThe Air Damping System has
two settings so that it can be ad-
justed to suit the type of surface
on which you intend riding.
You can turn the adjusting screw
any distance in either direction.
Adjusting damping for
rear wheelMake sure the ground is level
and firm and place the motor-
cycle on its stand.
Turn adjusting screw1to the
horizontal position.
Strong damping characteristic,
adjusting screw engages with
an audible click.
Turn adjusting screw1to the
vertical position.
Weak damping characteristic,
adjusting screw engages with
an audible click.
TyresChecking tyre pressureMake sure the ground is level
and firm and place the motor-
cycle on its stand.
Incorrect tyre pressures im-
pair the motorcycle's hand-
ling characteristics and increase
the rate of tyre wear.
Always check that the tyre pres-
sures are correct.
At high road speeds, tyre
valves have a tendency to
open as a result of centrifugal
force.
Fit metal valve caps with rubber
seals and screw them on firmly
to prevent sudden deflation.
Check tyre pressures against
the data below.
Tyre pressure, front
1.8 bar (one-up, tyre cold)
440zOperation

EngineEngine design Single-cylinder four-stroke, double overhead cam-
shafts driven by roller chain, 4 valves operated by
bucket tappets, balancing shaft, liquid-cooled cyl-
inder and cylinder head, integral water pump, 5-
speed gearbox and dry sump lubrication.
Displacement 652 cm
3
Cylinder bore 100 mm
Piston stroke 83 mm
Compression ratio 11.5:1
Nominal output 39 kW, - at engine speed: 7000 min
-1
Torque 60 Nm, - at engine speed: 5250 min
-1
Maximum engine speed max 7500 min
-1
Idle speed 1480 min
-1
10110zTechnical data