Honda CRF250F Owner's Manual Installation And Operation page 179

CRANKCASE BREATHER
Refer to the Safety Precautions on page 43.
Service more frequently if your motorcycle
is ridden in the rain or often at full throttle.
If the drain tube overflows, the air filter may
become contaminated with engine oil
causing poor engine performance.
• Drain the deposits by pinching the
(1)
crankcase breather tube (1).
(1) Crankcase breather tube
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