AD Boivin SNOW-HAWK 800 HO 2007 Shop Manual page 236

PERIODIC MAINTENANCE 2 - 10
2.8. ELECTRICAL SYSTEM
Spark plug
Check the general condition of the plug, the colour of its
electrodes, carbon deposits, plug gap and possible damage to
the gasket
A NGK BR9ECS spark plug is recommended.
Check the spark plug gap. The suggested gap is 0.45 mm
(0.018").
When tightening the spark plug, the torque must be between 25
and 30 N-m (18 and 21.5 lbf-ft; 2.5 and 3.0 kg-m).
Porcelain Colour
Light Grey (Overheated)
Blackish (Fouled)
The engine may be seriously damaged if the temperature
rating of the spark plug is inadequate.
Refer to the NGK codification on the next page.
Probable Cause
- Plug Temperature rating is too high
- Plug gap too wide
- Air/Fuel mixture too lean
- Stale gasoline
- Plug temperature rating too low
- Plug gap is too small
- Air/Fuel mixture too rich
- Oil/Fuel mixture too rich
CAUTION
Lean Normal
(light grey) (brownish)
Rich
(black)