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SPEC
MAINTENANCE SPECIFICATIONS
Piston:
Piston size “D”
46.960 ~ 46.975 mm (1.8488 ~ 1.8494 in)
Measuring point “H”
6.5 mm (0.256 in)
(From bottom line of piston skirt)
Piston over size: 2nd
47.50 mm (1.870 in)
4th
48.00 mm (1.890 in)
Offset
0.75 mm
Offset direction
Intake side
Piston clearance
0.025 ~ 0.045 mm (0.0010 ~ 0.0018 in)
<Limit>
<0.15 mm (0.006 in)>
Piston pin bore inside diameter
13.002 ~ 13.013 mm (0.5119 ~ 0.5123 in)
Piston pin outside diameter
12.996 ~ 13.000 mm (0.5117 ~ 0.5118 in)
Clutch:
Friction plate:
Thickness
×
Quantity
2.92 ~ 3.08 mm (0.115 ~ 0.121 in)
×
6
<Wear limit>
<2.9 mm (0.114 in)>
Clutch plate:
Thickness
×
Quantity
1.2 ~ 1.6 mm (0.047 ~ 0.063 in)
×
5
<Warp limit>
<0.06 mm (0.0024 in)>
Clutch spring:
Free length
×
Quantity
28.3 mm (1.11 in)
×
8
Clutch release method
Inner push, cam push
Clutch-in revolution
2,100 ~ 2,300 r/min
Clutch-stall revolution
2,800 ~ 3,000 r/min
Carburetor:
Type/manufacturer/quantity
VM16SH/MIKUNI/1
I. D. mark
5TH1 00
Main jet
(M.J.)
#76.3
Main air jet
(M.A.J.)
ø1.2
Jet needle-clip position
(J.N.)
3PZ 13-2
Needle jet
(N.J.)
D-8M
Cutaway
(C.A.)
3.5
Pilot jet
(P.J.)
#12.5
Pilot outlet
(P.O.)
ø0.7
Pilot screw
(P.S.)
1-1/8
Valve seat
(V.S.)
ø1.2
Fuel level
(F.L.)
2.5 ~ 4.5 mm (0.10 ~ 0.18 in)
Below carburetor body edge
Float height
(F.H.)
20.0 ~ 22.0 mm (0.79 ~ 0.87 in)
Engine idling speed
1,750 ~ 1,850 r/min
Intake vacuum
36 kPa (270 mmHg)
Model
YFM80WP
H
D
