Engine Break-In - Yamaha BIG BEAR YFM400NN Owner's Manual

EBU00209

Engine break-in

There is never a more important period in
the life of your machine than the period be-
tween 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
clearances.
During this period, prolonged full throttle
operation or any condition which might
result in excessive engine heating must be
avoided. However, momentary (2 ~ 3 sec-
onds maximum) full throttle operation un-
der load does not harm the engine.
Each full throttle acceleration sequence
should be followed with a substantial rest
period for the engine 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.
1. 0 ~ 10 hours:
Avoid continuous operation above
half throttle. Allow a cooling off period
of five to ten minutes after every hour
of operation. Vary the speed of the
machine from time to time. Do not op-
erate it at one set throttle position.
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