Onan MicroLite 4000 Series User Manual

3-2
All clearances are at 70° F (21° C) room temperature. All measurements are listed in inches with
millimeter measurements in parentheses. Measurements are for standard size parts.
FACTORY SPECIFICATION ALLOWABLE
DESCRIPTION MIN. MAX. LIMIT
Piston Pin
Piston Pin O.D. 0.7087 0.7089 0.7067
(Between Pin Bosses) (18.000) (18.005) (17.95)
Piston Rings
Top Compression Ring 0.0579 0.0587 0.0563
Thickness (1.47) (1.49) (1.43)
Second Compression Ring 0.0579 0.0587 0.0570
Thickness (1.47) (1.49) (1.45)
Top Compression Ring to Ring 0.0016 0.0032 0.0047
Groove Clearancce (0.04) (0.08) (0.12)
Second Compression Ring to 0.0008 0.0012 0.0039
Ring Groove Clearance (0.02) (0.06) (0.10)
Top Compression Ring End Gap 0.0120 0.0140 0.0197
(0.305) (0.356) (0.50)
Second Compression Ring End 0.0120 0.0140 0.0197
Gap (0.305) (0.356) (0.50)
Oil Ring Side Rail Gap 0.0120 0.0140 0.0197
(0.305) (0.356) (0.50)
Intake Valve
Valve Stem O.D. 0.2740 0.2746 0.2732
(6.960) (6.975) (6.940)
Valve Guide I.D. 0.2756 0.2762 0.2768
(7.000) (7.015) (7.03)
Valve Stem to Guide Clearance 0.0010 0.0022 0.0002/0.0035
(0.025) (0.055) (0.005/0.09)
Valve Stem to Rocker Arm 0.0008 0.0032 0.0008/0.0032
Clearance (Valve Lash) (0.02) (0.08) (0.02/0.08)
Face Angle 45° N/A

Onan MicroLite 4000 Series Specifications

General

Fuel Type	Gasoline
Frequency	60 Hz
Rated AC Output	4000 Watts
AC Voltage	120V
Rated AC Amperage	33.3A
Engine Type	OHV
Starting Method	Electric
Noise Level	68 dB at 23 ft