Honda Pioneer 1000 2017 Owner's Manual page 193

Refer to Safety Precautions on page 123.
1. Lift the cargo bed (page 81).
2. Remove the air cleaner outer cover (page 140).
3. Clean any dirt from around the spark plug base.
4. Disconnect the spark plug cap. Take care to avoid damaging the
spark plug wire when disconnecting the cap.
5. Using a spark plug wrench provided in the tool kit, remove the
spark plug.
6. Inspect the electrode and center porcelain for deposits, corrosion,
or carbon fouling. If the corrosion or deposits are heavy, replace
the plug.
7. Make sure that a 0.04 in (1.0 mm) wire-type feeler gauge cannot
be inserted between the spark plug gap. If the gauge fits in the
gap, replace the plug with a new one.
UNDER CARGO BED
spark plug caps
spark plug gap
(cont'd)