Specifications

Chapter 2 Fuel system and lubrication
57
7.2 Adjust idle speed by means of this screw
10 Air cleaner: removal, cleaning and replacement of
elements
1 Pull off the right-hand side panel to gain access to the air
cleaner case. Release the lid of the air cleaner case, then
displace the leaf spring to enable removal of the element. The
foam filter sleeves can be slid off the central core, and the whole
unit washer thoroughly in a high flash-point solvent such as
white spirit (Stoddard solvent). Dry each part carefully, then
soak each sleeve in the specified oil and squeeze it gently to
remove the surplus oil. Rebuild the assembly and refit it. Make
sure that the element and cover are both correctly seated to
prevent air leakage.
system is kept airtight, particularly at the exhaust port. Air leaks
here will cause mysterious backfiring when the machine is on
overrun, as air will be drawn in causing residual gases to be
ignited in the exhaust pipe. To this end, make sure that the com-
posite sealing ring is renewed each time the system is removed.
12 Oil pump: removal, examination and renovation
1 Access to the oil pump is gained after removing the right-
hand outer casing. The driving gear housing will be seen to have
two holes in its outer face. Turn the engine over until the holes
in the driving gear are in line, then pass a screwdriver through to
release the two countersunk retaining screws. The pump can
now be lifted away.
2 Remove the end plate from the back of the unit, noting the
locating pip and corresponding recess which must align during
reassembly. Shake out the inner and outer rotor. The driving
gear housing can be separated, if desired, and the gear and
spindle removed.
3 Examine each component for signs of scuffing and wear.
Note especially the condition of the rotors and pump body. If
these are at all worn, the pump must be renewed. Temporarily
fit the rotors to the pump body and use feeler gauges to
measure the clearance between the rotors and a straightedge
placed acoss the pump body mating surface (ie rotor endfloat).
This clearance should be in the range 0.15 - 0.20 mm (0.0059
— 0.0079 in) if the pump is in good condition; if the clearance
is 0.25 mm (0.0098 in) or more the worn components must be
renewed. Similarly measure the clearance between any two tips
of the inner and outer rotors. The correct clearance is 0.1 5 mm
(0.0059 in); if it is 0.20 mm (0.0079 in) or more the rotors must
be renewed as a matched set.
4 When reassembling the pump, lubricate each component
with clean engine oil, and make sure that a new gasket is fitted.
Note that the end plate pip and the depression in the pump
body must align. Fit new 0 rings when fitting the pump unit to
the engine.
11 Exhaust system: general
1 The exhaust system on a four-stroke motor-cycle will
require very little attention, as, unlike two-stroke machines, it is
not prone to the accumulation of carbon. The only points requir-
ing attention are the general condition of the system, including
mountings and the chromium plating, and ensuring that the
13 Oil filters: location and cleaning
1 The engine is equipped with two types of oil filter; a gauze
element located in the lower part of the left-hand crankcase,
behind a large hexagon-headed plug, and a crankshaft mounted
centrifugal oil filter. Removal and cleaning of these components
is covered in Routine Maintenance.
10.1a Air filter element is retained by spring clip
10.1b ... and can be dismantled for cleaning