Never run an engine when equipment is indoors. Breathing exhaust fumes can be fatal. Keep sparks and flames away from batteries - battery gas can explode. Use a flashlight to check the battery fluid level.
Never add fuel when the engine is running or hot. Add fuel outdoors where there is plenty of ventilation.
Follow fueling and pre-mixing instructions carefully for two-cycle engines. Wipe up any fuel spillage quickly to avoid the possibility of a fire.
Shut off the engine before servicing. On electrical start units, disconnect the battery ground cable before working on the electrical system. When working on two-cycle machines, remember to turn the unit switch off and disconnect the spark plug wire.