Yamaha ET250 User manual

FOREWORD
This service manual provides technical in-
formation on the 1980 models including its
features, differences from the 1979 models
and
new service procedure.
Please read
this manual thoroughly so that
you can have a good knowledge of the new
model and make best use of it in your sales
and after-service activities.
SERVICE DEPARTMENT
YAMAHA MOTOR CO,. LTD.
NOTE:
--~--- _
The Research and Engineering Departments
of Yamaha are continually striving to further
perfect all models. Improvements and
modifications are therefore inevitable.
In
light of this fact, all specifications within
this manual are subject to change without
notice.

Particularly important information is dis-
tinguished in
this manual by the following
notations:
NOTE:
A NOTE provides key information to make
procedures easier or cleaner.
CAUTION:
ACAUTION indicates special procedures
that must be followed to avoid change to the
machine.
WARNING:
A WARNING indicates special procedures
that must be followed to avoid injury to a
machine
operator or person inspecting or re-
pairing the machine.

·1980 ET250
CONTENTS
1. MODI·FICATIONS , ..
A. ENGINE , ...
8. DRIVE , 3
C. CHASSiS , 4
D. ELECTRICAL. , , 6
2. SERVICE 7
A. NEW SERVICE PROCEDURE 7
B. MAINTENANCE INTERVALS 10
C. SPECiFiCATIONS 12
D. SPECIAL TOOLS 17
E. WIRE ROUTING DIAGRAM 19
F. WIRING DIAGRAM 20
A. ENGINE
1. Left crank
Due to use of a new type clutch, the
crankshaft is tapered at its end to
mount the clutch.
'79 model
1. Left crank (8F3-11412-00)
. 2. Bearing (93306-30605)
3. Oil seal (93102-32161)
Interchangeability: No
(Refer to
"8. Drive, clutch.")
As a result. the bearing and oil seal in-
side diameters are changed from 32
mmto 30 mm.
'80 model
1. Left crank
(8J2-11412-00l
2.' 8earing(93306-30617)
3. Oil seal (93102-30188)
-1

1980 ET250
2. Starter
The air duct is no longer provided be-
cause there will be no problem of
overheating. Accordingly, the insert for
mounting
of the air duct on the starter
case is no longer used.
1. Air duct ...No longer used
(8G5-15471-001
2. Screw ... No longer used
(98506-050081
3. Plainwasher H' No longer used
(92906-05200)
4. Starter case
(8F3-15711-01 )
-2-
NOTE: ------------,---
The 1979 model can also be used without
installing the air duct.

B. DRIVE
Primary sheave
For better clutch operation and increased
durability, the new clutch has been adopted.
'79 model
1. Primary sheavecap complete
(8H7-17630-00l
2. Bolt
(90105-12009l
3. Washer
(90215-12084)
4. Washer
(90201-121911
5. Primary sliding sheavecomplete
(8F3-17620-00)
6. Compressionspring
(90501-55451)
7. Nut
190179-28088)
8. Washer
(90208-28003)
9. Spring set
(820-17644-00)
10. Cam
(8G5-17623-00)
11. Primary fixed sheavecomplete
(8E3-17610-00)
-3-
'80 model
1. Primary fixed sheave complete
(8H9-17610-00)
2. Primary sliding sheave
18H9-17621-00l
3. Bushing
(90389-39023)
4. Cap (8H9-17631-00l
5. 8ushing (90389-26022)
6. Bolt (97311-06025)
7. Boll(97311-06040)
B. Spring washer
(92902-06100)
9. Spider (8H9-17627-00)
10. Slide 18A7-17653-00)
11. Pin with hole
(90240-07066)
12. Plate washer
(90201-06589)
13. Weight (8H9-17632-001
14. Collar(90387-096981
Interchangeability:
1980 ET250
2
15. Collar (90387-06697)
16. Bolt IBH9-17647-00l
17. Plate washer
(90201-06053)
1B. Cotter pin
(91402-25012)
19. Compression spring
(90501·55345)
20. Cam (BJ2-17623-00)
21. Hexagon bolt
(90101-06440\
22. Self locking nut
(95601-06100)
23. Platewasher
(90201-06727)
24. Platewasher
(90201-09728l
25. Platewasher
(90201-06750)
No