ALMAC BiBi 850-BL, Use And Maintenance Manual

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BIBI 850-BL Use and maintenance manual Rev.00
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6.17 Spark plug inspection and replacement
To obtain a good performance, the gap between the electrodes of the spark plug must be correct and it
must be free from deposits. Comply with the instructions below:
1) remove the spark plug cap and clean off the dirt around the spark plug itself
2) remove the spark plug with a 13/16-inch wrench
3) visually inspect the spark plug and replace it if it is very worn or soiled, if the washer is in a bad
condition or if the electrode is worn
4) measure the gap between the spark plug electrodes with a wire gauge. Correct the distance as
required, by carefully bending the side electrode. The gap between the electrodes should be 0.7-
0.8 mm.
5) Carefully install the spark plug by hand to avoid screwing it in badly.
6) Once the spark plug has been housed, tighten it with a 13/16-inch spark plug wrench so as to
compress the washer.
NEW SPARK PLUG= tighten 1/2 of a turn once the spark plug has been housed, so as to
compress the washer
ORIGINAL SPARK PLUG= tighten 1/4-1/8 of a turn once the spark plug has been housed, so
as to compress the washer
RECOMMENDED SPARK PLUGS
BPR6ES (NGK)
W20EPR-U (DENSO) (Honda indications)
A spark plug that is too loose can overheat and damage the engine. The tip thread could be
damaged if the spark plug is tightened too much.
SPARK PLUG WRENCH SIDE ELECTRODE
WASHER