Onan NH User Manual

DESCRIPTION
MINIMUM MAXIMUM
Inches (mm) Inches (mm)
Y
.
PISTON PIN
Clearance in Piston ..............................................
Clearance in Connecting Rod
Nodular Iron Rod
..............................................
Aluminum Rod ................................................
Diameter ........................................................
PISTON RINGS
Clearance
Top Groove
...................................................
Ring End Gap in Cylinder ........................................
INTAKE VALVE
Stem Diameter ..................................................
Clearance (Stem to Guide) .......................................
Valve Face Angle ................................................
INTAKE VALVE SEAT
Seat Cylinder Head Bore Diameter ................................
Seat Outside Diameter ...........................................
Valve Seat Width ................................................
Valve Seat Angle ................................................
EXHAUST VALVE
Stem Diameter ..................................................
Clearance (Stem to Guide) .......................................
Valve Face Angle ................................................
EXHAUST VALVE SEAT
Seat Cylinder Head Bore Diameter ................................
Seat Outside Diameter ...........................................
Valve Seat Width ................................................
Valve Seat Angle ................................................
VALVE GUIDE
Inside Diameter .................................................
TAPPET
Body Diameter ..................................................
Bore Diameter ...................................................
Clearance in Bore ...............................................
VALVE SPRINGS INTAKE AND EXHAUST
Valve Spring Length
Valve Spring Free Length (Approx.)
...............................
Valve Open ....................................................
Spring Load @ 1.375 inch (Valve Closed) ..........................
Spring Load @ 1.125 inch (Valve Open) ...........................
Timing Gear. ....................................................
Oil Pump Gear ..................................................
Valve Closed ..................................................
GEAR BACKLASH
0.0001 (0.003) 0.0005 (0.013)
0.00005
(0.001)
0.00055 (0.014)
0.0002
(0.005) 0.0008
(0.020)
.
0.7500
(19.05) 0.7502
(19.06)
0.002
(0.051)
0.008 (0.203)
0.010
(0.254) 0.020
(0.508)
0.3425 (8.70) 0.3430 (8.71)
0.0010
(0.025) 0.0025 (0.064)
44"
1.5645
(39.74) 1.5655
(39.76)
1.5690
(39.85) 1.5700
(39.88)
0.031
(0.787) 0.047
(1.194)
45"
0.341
0 (8.661 ) 0.3420 (8.687)
0.0025 (0.064)
440
1.251
0
(31.78) 1.2520 (31.80)
1.2550
(31.88) 1.2560
(31.90)
0.031
(0.787) 0.047 (1.194)
45O
0.344 (8.74) 0.346 (8.79)
0.7475
(1 8.99) 0.7480 (1 9.00)
0.7505
(19.06) 0.7515
(19.09)
0.0015
(0.038)
0.003 (0.076)
1.662 (42.21)
I . 125 (28.58)
1:375 (34.93)
38Ib
. (17 kg) 42Ib . (19 kg)
71 Ib (32 kg) 79 Ib (36 kg)
0.002
(0.051) 0.003 (0.076)
0.002
(0.051)
0.005 (0.127)
5

Onan NH Specifications

General

Engine Model	NH
Cylinders	2
Fuel Type	Gasoline
Governor Type	Mechanical
Ignition System	Battery
Starter	Electric
Engine Type	4-cycle, air-cooled