Honda EM5000is Owner's Manual page 74

TECHNICAL & CONSUMER INFORMATION
Tampering and Altering
Tampering with or altering the emission control system may increase
emissions beyond the legal limit. Among those acts that constitute
tampering are:
Removal or alteration of any part of intake, fuel, or exhaust systems.
Altering or defeating the governor linkage or speed-adjusting
mechanism to cause the engine to operate outside its design
parameters.
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