Yamaha UMAX, Service Manual

Page: 84 / 320

6-MONTH CHECKS
3-11
2. Remove:
• Spark plug
Refer to “CYLINDER HEAD AND ROCKER
ARMS” on page 5-6.
NOTICE
Before removing the spark plug, blow away
any dirt accumulated in the spark plug well
with compressed air to prevent it from falling
into the cylinder.
3. Check:
• Spark plug type
Incorrect
→
Change.
4. Check:
• Electrodes “1”
Damage/wear
→
Replace the spark plug.
• Insulator “2”
Abnormal color
→
Replace the spark plug.
Normal color is medium-to-light tan.
5. Clean:
• Spark plug
(with a spark plug cleaner or wire brush)
6. Measure:
• Spark plug gap “a”
(with a wire thickness gauge)
Out of specification
→
Regap.
7. Install:
• Spark plug
TIP
Before installing the spark plug, clean the spark
plug and gasket surface.
8. Connect:
• Spark plug cap
CHECKING THE WIRE HARNESS (YUM2E)
1. Check:
• Wire harness
Cracks/frayed/corrosive
→
Replace.
CHECKING THE BRAKE CABLES
1. Check:
• Brake cables
Cracks/damage
→
Replace.
• Brake operation
Improper operation
→
Adjust the brake.
CHECKING THE SHOCK ABSORBERS
The following procedure applies to all of the
shock absorber assemblies.
1. Park the vehicle on a level surface and apply
the parking brake.
2. Check:
• Shock absorber assembly
Refer to “CHECKING THE FRONT SHOCK
ABSORBER ASSEMBLIES” on page 4-34
and “CHECKING THE REAR SHOCK AB-
SORBER ASSEMBLIES” on page 4-38.
• Operation
Pump the front shock absorber assembly up
and down several times.
Unsmooth operation
→
Replace shock ab-
sorber assembly.
Refer to “FRONT SUSPENSION COMPO-
NENTS” on page 4-32 and “REAR SUS-
PENSION COMPONENTS” on page 4-36.
CHECKING THE FUEL HOSE (YUM1A/
YUM2A)
1. Check:
• Fuel hose
Cracks/damage
→
Replace.
Loosen the connector
→
Connect properly.
Manufacturer/model
NGK/BPR4ES
Spark plug gap
0.7–0.8 mm (0.028–0.031 in)
T
R
.
.
Spark plug
20 N·m (2.0 kgf·m, 15 lb·ft)