SPECIFICATION SHEET

MACHINE SPEC.
Type	SUZUKI HM31A
Length	2,100mm
Width	695mm
Hight	1,185mm
Wheel base	1,425mm
Emgine type	M301
Weight, Front	87kgs
Weight, Rear	91kgs
Weight, Total	178kgs
ENGINE
Bore x Stroke	56.0 x 50.6
Compression ratio	7
Compression pressure	8.0kg/cm2/rpm
Weight (inc. Transmission)	50kgs
Intake open	145o BTDC
Intake close	55o ATDC
Exhaust open	90o BBDC
Exhaust close	90o ABDC
Scavenge open	60o BBDC
Scavenge close	60o ABDC
Idoling r.p.m.	1,500
TRANSMISSION
Primary gear ratio	2.23
Clutch facing size	132 x 111 x 2.8
Clutch facing Area x Piece	34 x 8
Transmision Gear ratio 1st	2.636
Transmision Gear ratio 2nd	1.750
Transmision Gear ratio 3rd	1.380
Transmision Gear ratio 4th	1.173
Transmision Gear ratio 5th	1.045
Transmision Gear ratio 6th	0.956
Final gear ratio	2.50 (16/41T)

MAINTENANCE DATE

PISTON/CYLINDER
Item	Standard	Limit
Clearance, Piston/Cylinder	0.05~0.06	0.12
Inner dia., Cylinder	56.0~56.05	56.65
Outer dia., Piston (25mm from lower end)	55.93~55.945	55.88
Surface level, Cylinder head	0~0.03	0.15
Free gap, Piston ring (1st)	4.7	3.76
Free gap, Piston ring (2nd)	4.7	3.76
Assembled gap, Piston ring (1st)	0.15~0.30	0.75
Assembled gap, Piston ring (2nd)	0.15~0.30	0.75
Clearance, Piston ring/Ring slot (1st)	0.03~0.09	-
Clearance, Piston ring/Ring slot (2nd)	0.02~0.06	-
Inner dia., Piston pin hole	14.002~14.010	14.034
Compression (kg/cm2)	8	5.6
Compression difference between each cylinder (kg/cm2)	-	1 kg/cm2
CRANK SHAFT
Item	Standard	Limit
Outer dia., Piston pin	13.995~14.000	13.965
Inner dia., Con-Rod Small end	18.003~18.011	18.039
End-Play, Con-Rod Small end	-	3
Thrust gap, Con-Rod Small end	0.2~0.62	1
Thrust gap, Con-Rod Big end	0.2~0.9	1
End-Play, Crank shaft	0~0.05	0.08
OIL PUMP
Item	Standard
Oil consumpsion (Oil pump full open, 2,000r.p.m., 2 min.)	7.1~7.6 cc
Adjust method, Oil pump control lever	Center mark
CLUTCH/PRIMARY GEAR
Item	Standard	Limit
Free play, Clutch lever	10~15
Thicness, Drive plate	2.8	2.5
Strain, Drive plate	0~0.25	0.4
Thicness, Driven plate	1.54~1.66	-
Strain, Driven plate	0~0.1	0.2
Free length, Clutch spring	35.8	34.01
Primary gear backrush	0.05
TRANSMISSION
Item	Standard	Limit
Thickness, Gear shift fork (1)	4.8~4.9	-
Thickness, Gear shift fork (2)	4.8~4.9	-
Thickness, Gear shift fork (3)	4.8~4.9	-
Width, Gear shift fork groove (1)	5.0~5.1	-
Width, Gear shift fork groove (2)	5.0~5.1	-
Width, Gear shift fork groove (3)	5.0~5.1	-
Gap, Gear shift fork/Groove (1)	0.1~0.3	0.5
Gap, Gear shift fork/Groove (2)	0.1~0.3	0.5
Gap, Gear shift fork/Groove (3)	0.1~0.3	0.5
Bend, Shift fork shaft	0~0.03	0.05
CARBULATOR
Item	Standard
Carbulator type	VM28
Main bore	28
Idoling r.p.m.	1,500
Fuel level	5.5
Main jet (M.J.)	120
Jet needle (J.N.)	5CM1-2
Needle jet (N.J.)	P-5
Throttle valve (C.A.)	2.5
Pilot jet (P.J.)	25
Air screw (A.S.)	1-5/8
Valve seat (V.S.)	2.5
Starter jet (G.S.)	50