Specifications - Yamaha ET250 Manual

1980 ET250
C. SPECIFICATIONS
General
NOTE:
* ...
New specification
(Compared with 1979 ET250)
Model:
Model (I.B.M. No.)
•
ET250('80) (8K3)
Frame 1.0. and starting number
• 8H7-054001
I
EngineLD. and starting number
• 5246-054001
Dimension:
Overall length
• 2.435 mm
Overall width {std] 905 mm
Overall height (w/windshield) 1,040 mm
Engine
Description:
Engine type
Fan cooled, two stroke
fi-port.
single cylinder
Engine model
5246
Displacement
246
crrr'
Bore X stroke 73
X
59mm
Effective compression ratio 6.3: 1
Starting system Recoil hand starter
Ignition system
C.O.I.
LlfIfricaflon system
.
fWt=e oilinjection
Cylinder head:
Combustion chamber volume (with spark plug)
32.1 crrr'
Compression chamber type
Dome
+
squish
Head gasket thickness
0.5mm
Cylinder:
Material Cast iron sleeves aluminum cylinder
Bore size 73 mm
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
(Measuring point)
(10 mm from piston skirt end)
Piston over size
1st 73.25 mm
2nd 73.50 mm
3rd 73.75 mm
4th 74.00 mm
Piston pin outside diameter X length 18
X
55 mm
Piston ring:
Piston ring
design (Top)
Keystone
Piston ring design [Znd]
Keystone
Ring end gap (Installed) (Top)
0.3~ 0.5 mm
Ring end gap (Installed) (Znd)
0.3~ 0.5 mm
Small end bearing:
Type
Needle bearing
Big end bearing:
Type
Needle bearing
Crankshaft:
Crankshaft assembly width (A)
+0
56
-0.05
mm
Crankshaft deflection (0) 0,02 mm
-12-