
Specifications
Engine
Service

GX22-25-31-35
OHV/OHC, Mini 4 stroke
GC series engines
Premium residential,
OHC, Horizontal crankshaft
GCV series engines
Premium residential,
OHC, Vertical crankshaft
GS series engines
Pro-sumer, OHC,
OHC, Horizontal crankshaft
GSV series engines
Pro-sumer, OHC,
OHC, Vertical crankshaft
GX Series engines
Commercial grade,
OHV, Horizontal crankshaft
GXV Series engines
Commercial grade,
OHV, Vertical crankshaft
Specifications subject to change
without notice.
OHV Horizontal engines
Pages 3 to 17
OHV Vertical engines
Pages 18 to 26
Liquid cooled engines
Page 27
Side Valve Horizontal engines
Pages 27 to 37
Side Valve Vertical engines
Pages 38 to 45
Oil used should be 10W-30
Unless otherwise specified
For propane applications
SAE 30 Wt oil can be used
© 2009 American Honda Motor Co., Inc.—All Rights Reserved

GC135, GC160, GC190
Oil Capacity
0.61 qt.
Transmission Oil
NA
Spark Plug
NGK BPR6ES
Spark Plug Gap
0.7 ~ 0.8 mm
0.028 ~ 0.031 in.
Float Height
9.2 mm (0.36 in.)
Engine RPM
Idle: 1,400 ± 150 rpm
Maximum: 3,850 ± 150 rpm
Compression
0.49 kPa (71 psi) @ 600 rpm
Valve Clearance
IN: 0.15 ± 0.04 mm EX: 0.20 ± 0.04 mm
GS190
Oil Capacity
0.58 qt.
Transmission Oil
NA
Spark Plug
NGK BPR6ES
Spark Plug Gap
0.7 ~ 0.8 mm
0.028 ~ 0.031 in.
Float Height
9.2 mm (0.36 in.)
Engine RPM
Idle: 1,400 ± 150 rpm
Maximum: 3,850 ± 150 rpm
Compression
0.49 kPa (71 psi) @ 600 rpm
Valve Clearance
IN: 0.15 ± 0.04 mm EX: 0.20 ± 0.04 mm
© 2009 American Honda Motor Co., Inc.—All Rights Reserved

GX22, GX31
Oil Capacity
0.11 qt.
Transmission Oil
NA
Spark Plug
NGK CR5HSB DENSO U16FSR-UB
Spark Plug Gap
0.6 ~ 0.7 mm
0.024 ~ 0.028 in.
Float Height
NA
Engine RPM
Idle: 3,100 ± 200 rpm
Maximum: 8,000 rpm
Compression
807-1096 kPa (117 ~ 159 psi)
@ 2,000 rpm
Valve Clearance
IN: 0.12 ± 0.02 mm EX: 0.15 ± 0.02 mm
GX25
Oil Capacity
0.08 qt.
Transmission Oil
NA
Spark Plug
NGK CMR5H
Spark Plug Gap
0.6 ~ 0.7 mm
0.024 ~ 0.028 in.
Float Height
NA
Engine RPM
Idle: 3,100 ± 200 rpm
Maximum: 8,000 ± 200 rpm
Compression
131 ~ 159 psi
Valve Clearance
IN: 0.08 ± 0.02 mm EX: 0.11 ±0 .02 mm
© 2009 American Honda Motor Co., Inc.—All Rights Reserved

GX35
Oil Capacity
0.11 qt.
Transmission Oil
NA
Spark Plug
NGK CMR5H
Spark Plug Gap
0.6 ~ 0.7 mm
0.024 ~ 0.028 in.
Float Height
NA
Engine RPM
Idle: 3,100 ± 200 rpm
Maximum: 10,000 rpm
Compression
138 ± 22
Valve Clearance
IN: 0.08 ± 0.02 mm EX: 0.11 ±0 .02 mm
GXH50
Oil Capacity
0.26 qt.
Transmission Oil
NA
Spark Plug
NGK CR5HSB DENSO U16FSR-UB
Spark Plug Gap
0.6 ~ 0.7 mm
0.024 ~ 0.028 in.
Float Height
12 mm (0.47 in.)
Engine RPM
Idle: 2,500 ± 200 rpm
Maximum No Load:
7,800 ± 150 rpm
Compression
422 kPa (61.2 psi) @ 1,000 rpm
Valve Clearance
IN: 0.08 ± 0.02 mm EX: 0.11 ±0 .02 mm
© 2009 American Honda Motor Co., Inc.—All Rights Reserved

GX100
Oil Capacity
0.42 qt.
Transmission Oil
NA
Spark Plug
NGK CR5HSB DENSO U16FSR-UB
Spark Plug Gap
0.6 ~ 0.7 mm
0.024 ~ 0.028 in.
Float Height
12 mm (0.5 in.)
Engine RPM
Idle: 1,550 ± 150 rpm
Maximum: 4,000 ± 200 rpm
Compression
0.49 kPa (71 psi) @ 700 rpm
Valve Clearance
IN: 0.15 ± 0.04 EX: 0.20 ± 0.04
GX110
Oil Capacity
0.63 qt.
Transmission Oil
1/2 reduction: 0.53 qt.
1/6 reduction: 0.16 qt.
Spark Plug
NGK BP6ES NGK BPR6ES
Spark Plug Gap
0.7 ~ 0.8 mm
0.028 ~ 0.031 in.
Float Height
13.7± 1.5 mm
0.54 ± 0.06 in.
Float Height
13.7± 1.5 mm
(0.54 ± 0.06 in.)
Engine RPM
Idle: 1,550 ± 150 rpm
Maximum: 4,000 ± 200 rpm
Compression
Decompressor engaged:
711 ± 123 kPa (103 ± 18 psi)
@ 600 rpm
Decompressor disengaged:
979 ± 193 kPa (142 ± 28 psi)
@ 600 rpm
Valve Clearance
IN: 0.15 ± 0.02 mm EX: 0.20 ± 0.02 mm
© 2009 American Honda Motor Co., Inc.—All Rights Reserved

GX120
Oil Capacity
0.63 qt.
Transmission Oil
1/2 reduction (centrifugal clutch type): 0.53 qt.
1/2 reduction (L t ype): Lubricated from engine
crankcase.
1/6 reduction: 0.16 qt.
Spark Plug
NGK BP6ES NGK BPR6ES
Spark Plug Gap
0.7 ~ 0.8 mm
0.028 ~ 0.031 in.
Float Height
13.7 mm (0.54 in.)
Engine RPM
Idle: 1,400 ± 150 rpm
Maximum: 3,850 ± 150 rpm
Maximum for DS type: 3,750 ± 150 rpm
Compression
Decompressor engaged: 711 ± 123 kPa
(103± 18 psi) @ 600 rpm
Decompressor disengaged: 979 ± 193 kPa
(142 ± 28 psi) @ 600 rpm
Valve Clearance
IN: 0.15 ± 0.02 mm EX: 0.20 ± 0.02 mm
GX140
Oil Capacity
0.63 qt.
Transmission Oil
1/2 reduction: 0.53 qt. 1/6 reduction: 0.16 qt.
Spark Plug
NGK BP6ES NGK BPR6ES
Spark Plug Gap
0.7 ~ 0.8 mm
0.028 ~ 0.031 in.
Float Height
13.7 ± 1.5 mm (0.54 ± 0.06 in.)
Engine RPM
Idle: 1,400 + 200 - 150 rpm
Maximum: 3,900 ± 150 rpm
Compression
Decompressor engaged: 711 ± 123 kPa
(103 ± 18 psi) @ 600 rpm
Decompressor disengaged: 979 ± 193 kPa
(142 ± 28 psi) @ 600 rpm
Valve Clearance
IN: 0.15 ± 0.02 mm EX: 0.20 ± 0.02 mm
© 2009 American Honda Motor Co., Inc.—All Rights Reserved

GX160
Oil Capacity
0.63 qt.
Transmission Oil
1/2 reduction (centrifugal clutch type): 0.53 qt.
1/2 reduction (L t ype): Lubricated from engine
crankcase.
1/6 reduction: 0.16 qt.
Spark Plug
NGK BP6ES NGK BPR6ES
Spark Plug Gap
0.7 ~ 0.8 mm
0.028 ~ 0.031 in.
Float Height
13.7 mm (0.54 in.)
Engine RPM
Idle: 1,400 ± 150 rpm Maximum: 3,850 ± 150 rpm
Maximum for (DS type): 3,750 ± 150 rpm
Compression
Decompressor engaged: 711 ± 123 kPa
(85 ~ 121 psi) @ 600 rpm
Decompressor disengaged: 979 ± 193 kPa
114 ~ 170 psi) @ 600 rpm
Valve Clearance
IN: 0.15 ± 0.02 mm EX: 0.20 ± 0.02 mm
GX200
Oil Capacity
0.63 qt.
Transmission Oil
1/2 reduction (centrifugal clutch type): 0.53 qt.
1/2 reduction (L t ype): Lubricated from engine
crankcase.
1/6 reduction: 0.16 qt.
Spark Plug
NGK BPR6ES W20EPR-U
Spark Plug Gap
0.7 ~ 0.8 mm
0.028 ~ 0.031 in.
Float Height
13.7 mm (0.54 in.)
Engine RPM
Idle: 1,400 + 200 -150 rpm
Maximum:3,850 ± 150 rpm
Compression
51.2 psi
Valve Clearance
IN: 0.15 ± 0.02 mm EX: 0.20 ± 0.02 mm
© 2009 American Honda Motor Co., Inc.—All Rights Reserved

GX240
Oil Capacity
1.16 qt.
Transmission Oil
1/2 reduction (centrifugal clutch type): 0.32 qt.
1/2 reduction (L t ype): Lubricated from
engine crankcase
1/6 reduction: Lubricated
from engine crankcase
Spark Plug
NGK BP6ES NGK BPR6ES
Spark Plug Gap
0.7 ~ 0.8 mm
0.028 ~ 0.031 in.
Float Height
13.2 ± 1.3 mm (0.52 ± 0.05 in.)
Engine RPM
Idle: 1,400 ± 150 rpm
Maximum: 3,850 ± 150 rpm
Compression
Decompressor engaged: 711 ± 123 kPa
(85 ~ 121 psi) @ 600 rpm
Decompressor disengaged: 979 ± 193 kPa
(114 ~ 170 psi) @ 600 rpm
Valve Clearance
IN: 0.15 ± 0.02 mm EX: 0.20 ± 0.02 mm
© 2009 American Honda Motor Co., Inc.—All Rights Reserved

GX270
Oil Capacity
1.16 qt.
Transmission Oil
1/2 reduction (centrifugal clutchtype): 0.32 qt.
1/2 reduction (L t ype): Lubricated from
engine crankcase
1/6 reduction: Lubr icated from engine
crankcase
Spark Plug
NGK BP6ES NGK BPR6ES
Spark Plug Gap
0.7 ~ 0.8 mm
0.028 ~ 0.031 in.
Float Height
13.2 ± 1.3 mm (0.52 ± 0.05 in.)
Engine RPM
Idle: 1,400 ± 150 rpm
Maximum: 3,850 ± 150 rpm
Compression
Decompressor engaged: 711 ± 123 kPa
(85 ~ 121 psi) @ 600 rpm
Decompressor disengaged: 979 ± 193 kPa
(114 ~ 170 psi) @ 600 rpm
Valve Clearance
IN: 0.15 ± 0.02 mm EX: 0.20 ± 0.02 mm
GX340
Oil Capacity
1.16 qt.
Transmission Oil
1/2 reduction: Lubricated from engine crankcase
1/6 reduction: Lubr icated from engine crankcase
Spark Plug
NGK BP6ES-11 NGK BPR6ES-11
Spark Plug Gap
1.0 ~ 1.1 mm (0.039 ~ 0.043 in.)
Float Height
13.2 ± 1.3 mm (0.52 ± 0.05 in.)
Engine RPM
Idle: 1,400 ± 150 rpm
Maximum: 3,850 ± 150 rpm
Compression
Decompressor engaged: 711 ± 123 kPa
(85 ~ 121 psi) @ 600 rpm
Decompressor disengaged: 979 ± 193 kPa
(114 ~ 170 psi) @ 600 rpm
Valve Clearance
IN: 0.15 ± 0.02 mm EX: 0.20 ± 0.02 mm
© 2009 American Honda Motor Co., Inc.—All Rights Reserved

GX340K1
Oil Capacity
1.16 qt.
Transmission Oil
1/2 reduction: Lubricated from engine crankcase
1/6 reduction: Lubr icated from engine crankcase
Spark Plug
NGK BP6ES NGK BPR6ES
Spark Plug Gap
0.7~0.8 mm (0.028~0.031 in.)
Float Height
13.2 ± 1.3 mm (0.52 ± 0.05 in.)
Engine RPM
Idle: 1,400 ± 150 rpm
Maximum: 3,850 ± 150 rpm
Compression
Decompressor engaged: 711 ± 123 kPa
(85 ~ 121 psi) @ 600 rpm
Decompressor disengaged: 979 ± 193 kPa
(114 ~ 170 psi) @ 600 rpm
Valve Clearance
IN: 0.15 ± 0.02 mm EX: 0.20 ± 0.02 mm
GX390K1
Oil Capacity
1.16 qt.
Transmission Oil
1/2 reduction: Lubricated from engine crankcase
1/6 reduction: Lubr icated from engine crankcase
Spark Plug
NGK BP6ES NGK BPR6ES
Spark Plug Gap
0.7~0.8 mm (0.028~0.031 in.)
Float Height
13.2 ± 1.3 mm (0.52 ± 0.05 in.)
Engine RPM
Idle: 1,400 ± 150 rpm
Maximum: 3,850 ± 150 rpm
Compression
Decompressor engaged: 711 ± 123 kPa
(85 ~ 121 psi) @ 600 rpm
Decompressor disengaged: 979 ± 193 kPa
(114 ~ 170 psi) @ 600 rpm
Valve Clearance
IN: 0.15 ± 0.02 mm EX: 0.20 ± 0.02 mm
© 2009 American Honda Motor Co., Inc.—All Rights Reserved

iGX440
Oil Capacity
1.16 qt.
Transmission Oil
NA
Spark Plug
NGK BKR7E-E DENSO K22PR-UR
Spark Plug Gap
0.7~0.8 mm (0.028~0.031 in.)
Float Height
13.2 ± 1.3 mm (0.52 ± 0.05 in.)
Engine RPM
3,600 rpm* *ECM base program
Compression
57 ~ 100 psi
Valve Clearance
IN: 0.12 ± 0.02 mm EX: 0.15 ± 0.02 mm
GX610, GX620
Oil Capacity
Without filter change: 1.27 qt.
With filter change: 1.59 qt.
Transmission Oil
NA
Spark Plug
NGK BP6ES NGK BPR6ES
Spark Plug Gap
0.7~0.8 mm (0.028~0.031 in.)
Float Height
14.0 mm (0.55 in.)
Engine RPM
Idle: 1,400 ± 150 rpm
Maximum: 3,850 ± 150 rpm
Compression
586 ~ 786 kPa (85 ~ 114 psi)
@ 500 rpm
Valve Clearance
IN: 0.15 ± 0.02 mm EX: 0.20 ± 0.02 mm
© 2009 American Honda Motor Co., Inc.—All Rights Reserved

GX610K1
GX620K1
Oil Capacity
Without filter change: 1.16 qt.
With filter change: 1.48 qt.
Transmission Oil
NA
Spark Plug
NGK ZGR5A
Spark Plug Gap
0.7~0.8 mm (0.028~0.031 in.)
Dry Fuel 0.3~0.4 mm (0.012~0.016 in.)
Float Height
14.0 mm (0.55 in.)
Engine RPM
Idle: 1,400 ± 150 rpm
Maximum: 3,850 ± 150 rpm
Compression
586 ~ 786 kPa (85 ~ 114 psi)
@ 500 rpm
Valve Clearance
IN: 0.15 ± 0.02 mm EX: 0.20 ± 0.02 mm
GX630
Without filter change: 1.59 qt.
With filter change: 1.80 qt.
Transmission Oil
NA
Spark Plug
NGK ZFR5F, FR2A
Spark Plug Gap
0.7~0.8 mm (0.028~0.031 in.)
Float Height
15.5 mm ( 0.61 in.)
Engine RPM
Idle: 1,400 ± 150 rpm
Maximum: 3,850 ± 150 rpm
Compression
499 ~ 7.00 kPa (73 ~ 102 psi)
@ 500 rpm
Valve Clearance
IN: 0.08 ± 0.02 mm EX: 0.10 ± 0.02 mm
Oil Capacity
© 2009 American Honda Motor Co., Inc.—All Rights Reserved

GX660
Oil Capacity
Without filter change: 1.59 qt.
With filter change: 1.80 qt.
Transmission Oil
NA
Spark Plug
NGK ZFR5F, FR2A
Spark Plug Gap
0.7~0.8 mm (0.028~0.031 in.)
Float Height
15.5 mm ( 0.61 in.)
Engine RPM
Idle: 1,400 ± 150 rpm
Maximum: 3,850 ± 150 rpm
Compression
499 ~ 7.00 kPa (73 ~ 102 psi)
@ 500 rpm
Valve Clearance
IN: 0.08 ± 0.02 mm EX: 0.10 ± 0.02 mm
GX670
Oil Capacity
Without filter change: 1.69 qt.
With filter change: 2.01 qt.
Transmission Oil
NA
Spark Plug
NGK ZGR5A
Spark Plug Gap
0.7~0.8 mm (0.028~0.031 in.)
Dry Fuel 0.3~0.4 mm (0.012~0.016 in.)
Float Height
15.0 mm (0.59 in.)
Engine RPM
Idle: 1,400 ± 150 rpm
Maximum: 3,850 ± 150 rpm
Compression
586 ~ 786 kPa (85 ~ 114 psi)
@ 500 rpm
Valve Clearance
IN: 0.15 ± 0.02 mm EX: 0.20 ± 0.02 mm
© 2009 American Honda Motor Co., Inc.—All Rights Reserved