LOSS OF POWER
Check ignition and carburetion and tune
engine if necessary.
Check compression. If compression rises
following wet test, ring and cylinder wear is
indicated. I f compression remains low during
wet test, valve and seat wear are indicated.
Check brake adjustment and condition; they
may be dragging.
Handlebar (kill) switch
Check wheel bearings for dirt, dryness, and
wear that may create drag.
Check compression (above). I f power
sudden, damage t o rings, piston, and bore or
valves and seats are more likely than wear.
Check the ignition system for a failed
component, poor contact, or change i n timing
or point gap. Check electronic module on
Check the fuel system for an obstruction.
carburetion. Poor performance at idle is
described earlier. Misfiring at low speed (just
above idle) can be caused by a dirty low-speed
circuit or jet (Figure 13). Poor midrange per-
formance is attributable to a worn or incor-
rectly adjusted needle and needle jet. Misfiring
at high speed (if not ignition related) is usually
caused by a too-large main jet which causes the
engine to run rich. Any of these carburetor-
related conditions can be corrected by first
cleaning the carburetor and then adjusting it as
described in the tune-up and maintenance
Loss of Power
First determine how the power loss developed
(Figure 14). Did it decline over a long period of
time or did it drop abruptly? A gradual loss is
normal, caused by deterioration of the engine's
state of tune and the normal wear of the
cylinder and piston rings and the valves and
seats. In such case, check the condition of the
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