8-5
Spark plugs are produced in several different thread lengths.
The thread length (reach) is the distance from the spark
plug gasket seat to the end of the threaded portion. If the
reach is too long, overheating and engine damage may
result. If the reach is too short, spark plug fouling and poor
performance may result. Also, if too short, carbon will form
on the exposed threads resulting in combustion chamber
hot spots and thread damage. Always use a spark plug with
the proper reach.
Spark plug reach
1
:
19.0 mm (0.75 in)
Before installing any spark plug, measure the electrode
gap with a wire thickness gauge and adjust to specification.
Spark plug gap
2
: 0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
When installing the plug, always clean the gasket surface.
Wipe off any grime from the threads and torque the spark
plug properly.
Spark plug torque: 20 Nm (2.0 m·kg, 14 ft·lb)
834-001
ESS52400
ENGINE IDLE SPEED ADJUSTMENT
CAUTION:
•
Be sure this adjustment is serviced by a Yamaha
dealer.
•
Be sure the throttle lever moves smoothly.
•
Be sure the carburetor is synchronized first.
1. Start the engine.
NOTE:
Refer to STARTING THE ENGINE.
2. Turn the throttle stop screw
1
in or out to adjust the
engine idle speed.
Standard engine idle speed: 1300
±
100 r/min
804-055