Husqvarna TE 250i Owner's Manual page 138

18 SERVICE WORK ON THE ENGINE
136
Danger
Danger of poisoning Exhaust gases are toxic and
inhaling them may result in unconsciousness and
death.
–
Always make sure there is sufficient ventilation
when running the engine.
–
Use an effective exhaust extraction system when
starting or running the engine in an enclosed
space.
–
Start the engine and check that it is oil-tight.