Yamaha ET250D Manual

_YAMAHA
supp
[Frame serial number: 8J5-038101
~ 8J5-049999 ]
Engine serial number: S246-038101
~ S246-049999
LIT -12618-00-22
8J5-28197-10

1980 ET250D
CONTENTS
(
1. NEW SERVICE PROCEDURE .. ................... ... . ..... . ... ................................. 1
2. MAINTENANCE INTERVALS
..... .... .. .. ............ ... ............... ... ................... .. 6
3. SPECiFiCATIONS
..... ................................... .. .... ... .......... .. ........ .... .............. 8
4. SPECIAL TOOLS
.. ......... .. .. ...... .... .... .. . ...... .. ... ... . ........ .... .. .... ........... .... ... ...... 13
5. WIRING DIAGRAM ... . ... . ... ... .. . .. . .. .................................... .. ....... ... .... . ... ... ... 14
( 6. WIRE ROUTING
DIAGRAM/PIPING AND CONTROL
CABLE DIAGRAM ... ........ ................... .... .. ........................ ... ................... .... 15
1. NEW SERVICE PROCEDURE
(N ew service procedure applied to the 1980 ET250D)
c A.
Primary sheave
For better clutch operation and durability, a
new clutch has been adopped.
2
1. Primary fixed sheave
C
2_
Primary sliding sheave
3 _ Bushing (Large)
4_ Cap
5_ Bushing (Small)
6_
Bolt
7_
Bolt
8_
Spring washer
20
9 _ Spider
10_
Sl ider
11. Pin with hole
4
12 _ Plate
washer
C
13 _
Weight
14_
Collar
15_
Collar
16_
Bolt
17_
Plate washer
18_
Cotter pin
19_
Compr ession spring
5
20_
Cam
21. Hexagon bolt
C
22_
U- nut
23_
Plate washer
24_
Plate washer
- 1-

1980 ET250D
1. Removal
a. Remove the primary sheave mounting
bolt using the sheave holder.
Tool name Tool No.
Sheave holder
90890-01880
1. Sheave holder
b. Remove the primary sheave assembly,
using the primary fixed sheave puller
bolt and primary sheave holding tool.
Tool name
Primary fixed sheave puller
bolt (M 18 Pl.5)
1. Primary fixed sheave puller bolt
2. Disassembly
Tool No.
90890 - 01881
a. Separate the sliding sheave assembly
from the fixed sheave by rotating the
sliding sheave counterclockwise.
- 2-
b. Install the sheave sub-assembly tool to
the primary sheave.
Tool name Tool No.
Sheave sub-assembly
tool
90890-01879
1 Sheave sub-assembly tool
c. Loosen the six bolts securing the
primary sheave cap and sliding sheave.
d. Remove the sheave subassembly tool.
The primary sheave cap and sliding
sheave cap now be disassembled.
3. Inspection
a. Check the tapered ends of the crank-
shaft and
primary fixed sheave for
scratches. If scratched unduly, replac
e.
If scratches are minor, burnish with
emery cloth.
b. Check the primary sheave cap bushing
and sliding sheave
bushing for wear. If
beyond tolerance, replace the bushing.
bushing clearance, limit
Small bushing Large bushing
Inside 0.
25 mm (0.01 in) 0.
25 mm (0.01 in)
Outside
0.25 mm (0.01 in) 0. 25 mm (0.01 in)
)
)

r
c
(
c
c
c
NOTE:--------------------------
If bushing is installed tightly, remove the bu-
shing using the bushing tool.
-3-
1980 ET250D
Tool name Tool No.
Bushing
tool 90890-01877
1. Bushing tool
c. Check the compression spring for free
length. If excessively fatigued, rep!ace.
d. Check the spider and roller for smooth
movement and wear.
e. Check both sheaves for warping. If
warped, replace.
4. Reassembly
a. Oil the points shown in the illustration.
Do not apply the grease on the portion
of X mark. For other parts, greasing is
unnecessary.
+- X Free from grease
+- Greasing point
CAUTION:-------------------,
If the U -nut or cotter pin is removed for
the greasing, replace it with new one.

1980 ET25lJD
b. Install the component parts to the slid-
ing sheave and the sheave cap.
NOTE:-- ---- ------------------ --
When installing the primary sheave cap to
the primary sliding sheave, be sure to align
the X mark on the sheave cap with that on
the spider.
c. Install the sheave subassembly tool and
tighten the cap.
d. Tighten the six primary sheave cap bolts
and remove the subassembly tool.
Tightening torque:
1.1 m-kg (8 ft-Ib)
CAUTION: --------------,
Make sure that the primary sheave cap
assembly slides in contact with the
fixed sheave boss.
-4-
e. Clean the taper ed portions of crankshaft
and fixed sheav
e.
f. Fit the fixed sheave to the tapered por-
tion of crankshaft.
g.
Apply engine oil to the threaded portion
of primary sheave bolt and its contact
surface with spring washer.
,
h. Tighten the primary sheave mounting
bolt using primary sheave cap holding
tool.

Tightening torque :
First
tight en the bolt to a torque of
A then loosen it.
Retightened
bolt to a final torque of
B.
A.: 10m-kg (72 .5 ft-Ibl
B. : 6 m-kg (43.5 ft-Ibl
B. Starter
The air duct is no longer provided because
there
will be no problem of overheating. Ac-
cordingly, the insert for mounting of the air
duct on the starter case is no longer used.
1.
Air duct .. . No l onger used
2.
Screw ... No longer used
3. Plain
wash er ... No longer used
4.
Starter case
NOTE:------ ------ -------- ------
.The 1979 model can also be used without
installing the air duct .
19 80 ET250D
- 5 -

1980 ET250D
2. MAINTENANCE INTERVALS
[PERIODIC MAINTENANCE]
Every
Check point
20 hrs. or 40 hrs. or
80 hrs or
When
Seasonally
400 km 800 km
1600 km
necessary
(2
50 mil (500 mil
(1000 mil
ENGINE
Tightness of bolts and nuts
0 0
Bends. cracks and wear
0 0
Abnormal noise 0 0
Loose connection and breaks of fuel and pulse pipes 0 0
Loose connection and breaks of oil pipes
0 0
Loose connection and breaks of oil delivery pipe 0 0
Manual r ope starter system
0 0
Carbu retor
• Fuel level 0 0
•
Operation of starter jet
0 0
•
Mixing adjuster (pilot screw) 0 0
•
Idling speed adjustment
0 0
Operation and adjustment of oil pump
0 0
Ignition timing
0
Cylinder comp ressions 0 0
Cylinder head/exhaust pipe decarbonize 0
Spark plug condition. gap and cleaning
0 0
Tightening of the cylinder head"
0
DRIVE:
Tightness of bolts and nuts
0 0
Wear on slide runners
0 0
Primary drive system
0 0
V-belt
0 0
Secondary drive system
0 0
Sheave distance
0 0
Sheave offset
0 0
Brake pad wear
0 0
Brake operation and adjustment
0 0
Guide wheel rubber 0 0
Wear of drive track wheel sprocket
0 0
Initial
100 km
Drive
track adjustment
(60 mil
0 0
and
300 km
(200 mil
Breaks in drive track
0 0
Bends in front and rear axles 0 0
Checking of lock washers
0 0
"-
Drive chain adjustment 0 0
Drive chain oil level 0 0
BODY
Tightness of bolts and nuts 0 0
Bends and cracks 0 0
Welded riveted. joints
0 0
Ski adjustment
0 0
Ski runner wear 0 0
Breaks in fuel tank
0 0
Cleaning of fuel tank
0
F,uel filter
0
Loose connection and breaks in fuel pipe
0 0
Breaks in oil tank
0 0
Oil filter
0
- 6 -

1980 ET250D
Every
Check point
20 hrs. or 40 hrs. or 80 hrs or
When
Seasonally
400 km 800 km 1600 km necessary
(250 mil (500 mil (1000 mil
ELECTRICAL:
Wear , breakage of wire covering 0 0
Breaks in high-tension cord 0 0
Voltage regul ator working voltage 0
Operation of engine stop switch
0 0
Operation of tether switch
0 0
Headlight
0 0
Taillight 0 0
Brake light
0 0
•• R etight en every 10 hours from the first use.
[LUBRICATION INTERVALS]
Eve ry
Lubrication
point
20 hrs, or 40 hrs. or 80 hrs, or
When
Seasonally Oil/Grease
400 km
8 00 km 1,600 km
necessary 8rand name
(2 50 mil (500 mil (1.000 mil
ENGINE:
Starter case 0
Oil pump contro l box
0 0 Aeroshell grease #7A
or
Esso Beacon 325 grease
Pump drive cover 0 0
Oil in the oil tank
0
YAMALUB E 2-cycle oil
DR I VE :
Primary sheave weight
0 0
and roller pins
Molybdenum disulf ide
Secondary shaft and 0
snowmobile grease
sliding sheave 0
Front axle hous ing 0 0
Shaft 1 and shaft 2 0
Light all-purpose grease
(Slide raill 0
Drive chain oil 0 Gear oil API "GL-
3"
replacement
0
SAE#750r # 80
BODY:
Steering column lower
0 0 Light all-purpose grease
bearing
Steering colu
mn upper
0 0
Motor oil
bearing
Steering links 0 0
Ski column
0 0
Ski wear plate 0 Light all-purpose grease
0
Ski retaining pin 0 0
Brake wire end stopper
0 0 Esso
8eacon 325 grease
and brake lever
-7 -

1980 ET250D
3. SPECIFICATIONS
General
NOTE: * ... New specification
(Compared with 1979 ET250C)
Model:
Model (I.B.M.
No)
*
ET250D (8J5)
Frame 1.0. and starting number
* 8J5-038101
Engine 1.0. and starting number
*
S246 -0 381 01
Dimension:
Overall l engt h 2.
385 mm (93.9 in)
Overall width (std)
905 mm (35.6 in)
Overall height (w / windshield)
965 mm (38.0 in)
Engine
Description:
Engine type
Fan cooled. two stroke 5-port. single cylinder
Engine model S246
Displacement
246 cm3 (15 cu.in)
Bore X stroke
73 X 59 mm (2.87 X 2.3 in)
Effective
compression ratio
6.6: 1
Starting system Recoil hand starter
Ignition system C.D.1.
Lubrication system
"Autolube" oil injection
Cylinder head
Combustion chamber volume (with spark plug) 29.6cc(1.81 cu.in)
Compression chamber type Dome + squish
Head
gasket thickness
0.5 mm (0.02 in)
Cylinder:
Material Cast iron sleeves alu minum cylinder
Bore size
73 mm (2.87 in)
Taper
limit 0.05 mm (0.0020 in)
Out of round limit 0.01 mm (0.0004 in)
Piston:
Piston
skirt clearance
0.045 ~ 0.050 mm (0.00 18 ~ 0. 0020 in)
(Measuring point) (10 mm from pis ton skirt end)
Piston
over size 1st
73 . 25 mm (2.88 in)
2nd 73.50 mm (2.89 in)
3rd 73.75 mm (2 .90 in)
4th 74.00 mm (2.91 in)
Piston pin outside
diameter X length 18 X 55 mm (0.71 X 2.17 in)
Piston ring:
Piston ring design (Top) Keystone
Piston ring design (2nd) Keystone
Ring end gap (Installed) (Top)
0.3 ~ 0.5 mm (0.012 ~ 0.020 in)
Ring end gap (Installed) (2nd)
0.3 ~ 0.5 mm (0.012 ~ 0.020 in)
Small end bearing:
Type Needle bearing
Big end bearing:
Type Needle bearing
Crankshaft:
Crankshaft assembly
width (A)
+0 +0.
56 _ 0.05 mm (2.2 _ 0.002 In)
Crankshaft deflection (D) 0.02 mm (0. 0008 in)
- 8-

1980 ET250D
Connecting rod large end side clearance (C)
0.5 mm (0.02 in)
Connecting rod small end def l ection (S) 2
mm (0 . 079 in)
A
r-----
D -
rrD~
cj~
40 mm 116 in)
40 mm 11.6 in)
I -S
Crank pin outside diameter X length
24 X 55 mm (0 . 945 X 2.165 in)
Crank pin type
Solid shaft
Crank bearing type (Left) X q'ty
* #
6306 C3 special treatment x 1 pc.
Crank bearin g type (Right) X q'ty
#6206 C3 X 1 pc
Crank oil seal type (Left) X q'ty
* FPJ
30-72 -8 x 1 pc.
Crank oil seal type (Right) X q'ty
FPJ30-48-8 X 1 pc.
Carburetor:
Type and manufacture / quantity
CDX38-32 KEIHIN SEIK I X 1
I.D. mark
8G501
Main jet (M.J)
#13 8
Slow adjusting screw (Air screw) ( SA )
2.0 turns out
Slow
jet (SJ.)
# 50
Intermediate jet (I.J.) #
38
St arter jet (St.J.)
0.95 mm (004 in)
Fuel level
(F. L.) +5 ± 3.5
mm (0.20 ± 0.14 in)
Idling engine speed
1,300 r/ min
Main jet setting chart:
~
-30°C
- 20 °C -
10 °C O°C 10 °C
20 °C
Altitud~ .
1- 22 °F)
1- 4° F) 114° F) 132° F) 150° F) 168° F)
#138
Sea level .
#130
!
- 600m 12000 It)
#138
.
#1 30
;
- 1200m (4000 It)
#138
.
#130
- 1800m 16000 It) - #
138-
-#125--
#130
#1 30
- 2400m 1 8000 It)
#12 5 -
# 125 -
-
3000m 110000 It) or more . #
120 -
-Change
the Slow jet to #45
Change the slow adjusting screw to 1-1/4 - 1 -1 / 2 turns out.
Lubrication:
Autolube pump - Color code
Green
Autolube pump - Minimum stroke 0. 20 ~ 0.25 mm (0.008 ~ 0.01 in)
Autolube pump - Maximum stroke 1 .85 ~ 205 mm (0.073 ~ 0.081 in)
Autolube pump - Reduction ratio
1/ 40
Autolube pump - Output Min.
1 3.5 cc/h/l,300 r/min (0.46 oz/h/l,300 r/min)
Autolube pump - Output Max.
440 cc/h/6,500 r/min (14 .9 oz/h/6,500 r/min)
Oil tank capacity
2.2 liter (2.3 U.S. qt)
Oil grade
YAMALUBE 2-cycle oil
- 9 -