Honda VT750C2B Owner's Manual page 209

Catalytic Converters
Defective catalytic converters contribute
to air pollution, and can impair your
engine's performance. Follow these
guidelines to protect your motorcycle's
catalytic converters.
Always use unleaded gasoline. Even a
small amount of leaded gasoline can
contaminate the catalyst metals, making
the catalytic converters ineffective.
Keep the engine in good running
condition.
A poorly running engine can cause the
catalytic converter to overheat causing
damage to the converter or the
motorcycle.
202
Technical Information
If your engine is misfiring, backfiring,
stalling, or otherwise not running
properly, stop riding and turn off the
engine. Have your motorcycle serviced
as soon as possible.