heating YAMAHA YFZ450 2005 Owners Manual

6-19
EBU02092
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 fol-
lowed with a substantial rest period for the engine
by cruising at lower r/min so the engine can rid it-
self of the temporary build up of heat.
If any abnormality is noticed during this period,
consult a Yamaha dealer.
U5TG61.book Page 19 Friday, April 2, 2004 11:28 AM

8-71
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 air filter element maintenance is
performed, check the air inlet to the air filter case
for obstructions. Check the air intake duct between
the air filter case and the carburetor and the mani-
fold fittings for an airtight seal. Tighten all fittings
securely to avoid the possibility of unfiltered air en-
tering the engine. _CAUTION:_ Never operate the engine with the air filter ele-
ment removed. This will allow unfiltered air to
enter the engine, causing rapid engine wear
and possible engine damage. Additionally, op-
eration without the air filter element will affect
carburetor jetting with subsequent poor per-
formance and possible engine overheating. _
U5TG61.book Page 71 Friday, April 2, 2004 11:28 AM

8-148
Engine overheatingNOTE:_ If it is difficult to get the recommended coolant, tap water can be temporarily used, provided that it is
changed to the recommended coolant as soon as possible. _
WARNING
_ Wait for the engine and radiator to cool before removing the radiator cap. You could be burned by
hot fluid and steam blown out under pressure. Always put a thick rag over the cap when opening.
Allow any remaining pressure to escape before completely removing the cap. _ Wait until the
engine has cooled.
Check the coolant level in the
coolant reservoir and/or radiator.
Level is OK.Level is low, check the
cooling system for leakage.
No
leakage.Leakage.
Ask a Yamaha dealer to inspect
and repair the cooling system.Add coolant. (See NOTE.)
Restart the engine. If the engine overheats again, ask a
Yamaha dealer to inspect and/or repair the cooling system.
U5TG61.book Page 148 Friday, April 2, 2004 11:28 AM