Honda HRX537C Owner's Manual page 47

Spark Plug Service
Recommended spark plugs: NGK - BPR6ES
The spark plugs listed above have an internal resistor. Resistor spark plugs
reduce interference with radio and TV reception.
NOTICE
Incorrect spark plugs can cause engine damage.
For good performance, the spark plug [1] must be properly gapped and free of
deposits.
1. Disconnect the spark plug cap [2]
and remove any dirt from around
the spark plug area.
2. Remove the spark plug [1] with a
spark plug wrench [3].
E
DENSO - W20EPR-U
[1]
7. MAINTENANCE
[2]
[3]
47