Adjusting The Air Valve Gap; Brake Checking - Baja 49CC DIRT RUNNER Owner's Manual

ADJUSTING THE AIR VALVE GAP

The engine will make excess noise if the gap is too large in the air valve. If the gap is
too small valve operation will be hindered which could result in valve malfunction and
failure. Therefore, the air valve gap must be checked periodically.
The gap of the air valve should be inspected and adjusted when the engine is cold by
using the following procedures. This procedure should only be performed by a qualified
motorcycle technician at a service center:
 Remove the caps of the central hole and the top hole (the ignition timing
observation hole) in the left crankcase cover.
 Remove the caps of the two air valves on the cylinder head.
 Insert the "T" key into the central hole of the crankcase cover, jam it against the nut
of the flying wheel and then turn the flying wheel clockwise until the engraved "T"
mark on the flying wheel aligns with the engraved line on the top of the crankcase
cover. Swing the rocking arm slightly. A loose rocking arm (which indicates the
existence of clearance) shows that the piston is in the upper stop position of the
compressing stroke, where the valve can be adjusted. A tight rocking arm means
that the piston is in the lower stop position of the compressing stroke. In this case,
continuously turn the "T" key clockwise for 360 degrees until the alignment of those
engraved marks, where the valve can be adjusted. Afterwards, check the valve gap
by inserting a feeler in between the valve adjusting screw and the end of the valve.
The specified air valve gap: 0.05mm for the intake and exhaust valves respectively.

BRAKE CHECKING

 Remove the front and rear brakes respectively and check for wear of the brake
shoes. If the mark "∆" on the brake drum cover aligns with that "∆" on the brake
cam, it means that the brake shoes are already worn to the limit and have to be
replaced.
 Replacement should be carried out at a designated service center and it is
recommended that only original replacement parts are used.
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