Spark plug cap
0.70–0.80 mm
Plug wrench
Side electrode
16
3-5 Spark Plug Service
3-5 Spark Plug Service
1. Remove the spark plug cap. Clear away
dirt around the spark plug base.
2. Use the plug wrench to remove the spark
plug.
3. Visually inspect the spark plug if the insu-
lator is cracked, if cracked, replace with
new the spark plug, if deposit around the
electrode, remove carbon or other depos-
its with a stiff wire brush.
4. Measure the spark plug clearance with a
feeler. The clearance should be 0.7–0.8
mm. If needing adjusting, lightly tap (for
gap too big) or pry up with flat screwdriv-
er (for gap too small) electrode.
5. Check that the spark plug washer is in
good condition.
6. Install the spark plug on and screw down
it with plug wrench, compress the plug
washer. Cover the spark plug cap on.
TIP
To avoid cross-threading, first, screw in spark
plug by hand, then tighten with a spark plug
wrench to compress the gasket.
If a new spark plug is used, more twist 1/2
turns after compressing the gasket.
If reinstalling the used spark plug, just more
twist 1/8–1/4 turns.
Spark plug:
22±2 N·m
The spark plug must be tightened securely, or
it may become very hot to damage the engine.
When replaced, please pay attention to model
of the spark plug to avoid to damage the
engine or use recommended spark plug or the
equivalent. Incorrect heat range of the spark
plug may damage the engine.
MA190 recommended spark plug
model:
NGK (BPR6HS or BPR7HS)
CHAMPION (RL82YC or RL87YC)
TORCH (E7RTC or E6RTC)