Checking The Thermostat - Yamaha 2004 YP400 Service Manual

THERMOSTAT
EAS00462

CHECKING THE THERMOSTAT

1. Check:
• thermostat 1
Does not open at 70.5 ~ 73.5 °C (158.9 ~
164.3 °F) → Replace.
M MMM M MMM M M MMM
a. Suspend the thermostat in a container filled
with water.
b. Slowly heat the water.
c. Place a thermometer in the water.
d. While stirring the water, observe the ther-
mostat and thermometer's indicated tem-
perature.
L LLL L LLL L L LLL
1 Thermostat
2 Container
3 Thermometer
4 Water
È Fully closed
É Fully open
NOTE:
_
If the accuracy of the thermostat is in doubt,
replace it. A faulty thermostat could cause seri-
ous overheating or overcooling.
2. Check:
• thermostat cover
Cracks/damage → Replace.
3. Check:
• thermostat inlet hose
• thermostat outlet hose
Cracks/damage → Replace.
6 - 5
COOL
M M MMM M M MMM M
L L LLL L L LLL L
M MMM M MMM
L LLL L LLL