Yamaha TTR90(M) Owner's Service Manual page 280

CARBURETOR HEATING SYSTEM
6 - 7
EC624000
COUPLERS AND LEADS CONNECTION
INSPECTION
1. Check:
Couplers and leads connection
Rust/dust/looseness/short-circuit
Repair or replace.
CDI MAGNETO INSPECTION
1. Inspect:
Source coil resistance
Refer to "IGNITION SYSTEM" section.
THERMO SWITCH INSPECTION
1. Inspect:
Thermo switch operation
Faulty operation
Inspection steps:
Remove the thermo switch.
Connect the pocket tester to the thermo
switch coupler as shown.
Tester (+) lead
Tester (–) lead
Immerse the thermo switch in a container
filled with water 3.
Place a thermometer 4 in the water.
Slowly heat the water, and then let it cool to
the specified temperature as indicated in
the table.
Check the thermo switch for continuity at
the temperatures indicated in the table.
–
ELEC
Replace.
black 1
black 2
+