Honda GC135 Owner's Manual page 8

ENGINE SAFETY
Carbon Monoxide Hazard
Exhaust gas contains poisonous carbon monoxide. Avoid inhalation of
exhaust gas. Never run the engine in a closed garage or confined area.
Other Equipment
Review the instructions provided with the equipment powered by this
engine for any additional safety precautions that should be observed
i n conjunction with engine startup, shutdown, or operation, or
protective apparel that may be needed to operate the equipment.
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