Spark Plug; Spark Plug Gap; Condition Of Electrode / Insulator - BRP Johnson 4HP Service Manual

SPARK PLUG

•
INSPECT EVERY 100 HOURS (6 MONTHS).
•
REPLACE EVERY 200 HOURS (12 MONTHS).
Standard spark plug: NGK BPR6ES
Only resistor (R) type spark plugs must be used with this
engine. Using a non-resistor spark plug will cause igni-
tion system malfunctions.

Spark Plug Gap

Measure for the spark plug gap using the thickness gauge.
Adjust to within the specified range if the gap is out of the
specification.
Spark plug gap: 0.7 – 0.8 mm (0.028 – 0.031 in)
 Thickness gauge

Condition of Electrode / Insulator

Check the electrode and insulator condition.
If the electrode is extremely worn or burnt, replace the spark
plug.
If the spark plug has a broken insulator, damaged threads,
etc., replace the spark plug.
Confirm the thread size and reach when replacing the
plug. If the reach is too short, carbon will be deposited
on the threaded portion of the plug hole resulting in pos-
sible engine damage.

Spark plug: 28 N·m (2.8 kg-m; 20.0 lb-ft)
PERIODIC MAINTENANCE
SPARK PLUG
Gap
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