6-15
EBU02101
Engine break-in
There is never a more important period in the life of
your machine than the period between zero and
20 hours.
For this reason, we ask that you carefully read the
following material. Because the engine is brand
new, you must not put an excessive load on it for
the first several hours of running. During the first
20 hours, the various parts in the engine wear and
polish themselves to the correct operating clear-
ances.
During this period, prolonged full throttle operation
or any condition which might result in excessive
engine heating must be avoided. However, mo-
mentary (2–3 seconds maximum) full throttle oper-
ation under load does not harm the engine.
Each full throttle acceleration sequence should be
followed with a substantial rest period for the en-
gine by cruising at lower r/min so the engine can
rid itself of the temporary build up of heat. If any
abnormality is noticed during this period, consult a
Yamaha dealer.
U5UH60.book Page 15 Wednesday, October 8, 2003 9:05 AM
8-55
NOTE:_ The air filter element should be cleaned every 20–
40 hours. It should be cleaned and lubricated more
often if the machine is operated in extremely dusty
areas. Each time the air filter element mainte-
nance is performed, check the air inlet to the filter
case for obstructions. Check the air filter case rub-
ber joint to the carburetor and manifold fittings for
an airtight seal. Tighten all fittings securely to
avoid the possibility of unfiltered air entering the
engine. _CAUTION:_ Never operate the engine with the air filter ele-
ment removed. This will allow unfiltered air to
enter, causing rapid engine wear and possible
engine damage. Additionally, operation with-
out the air filter element will affect carburetor
jetting with subsequent poor performance and
possible engine overheating. _
U5UH60.book Page 55 Wednesday, October 8, 2003 9:05 AM
