- 14 -
MAINTENANCE
(continued)
TORQUE CHART (INCH/LB)
Pump Type
Direct Drive
K12
K17
K18
K24
K28
K30
Head Bolts
96
243
243
243
243
347
347
Cylinder Bolts
120
182
182
182
182
330
330
Bearing-Carrier Bolts
N/A
130
130
130
130
130
130
Connecting-Rod Bolts
N/A
121.5
121.5
121.5
121.5
121.5
173.6
Flywheel Nut (left-hand thread)
N/A
243
382
382
382
477
477
Determine pump type using suffix of Model number (Example: 4090HK17 uses K17 pump)
PILOT VALVE ADJUSTMENT
NOTE: Should only be performed by ROLAIR factory authorized personnel.
RESETTING DIFFERENTIAL (2)
Make sure the top toggle lever is positioned as shown. (See Figure 3). Loosen locknut (1) by
turning counterclockwise several full turns. Gently turn differential setting (2) clockwise only until the
internal rod makes contact with the steel ball inside. After making contact, turn differential (2)
counterclockwise 1/4 turn. Secure position by tightening locknut (1) and proceed to top end setting.
TOP-END SETTING (4)
Loosen locknut (3) by turning counterclockwise several full turns. (4) is the top end setting.
Turning (4) clockwise will increase the top end pressure setting. Turning counterclockwise will decrease
the top end pressure setting. Begin at a low setting by turning counterclockwise one full turn. Proceed
to fine tuning instructions.
FINE-TUNING INSTRUCTIONS
Start engine/motor and observe tank pressure gauge. As tank pressure approaches 100-130
P.S.I.G., the pilot valve should begin unloading at felt muffler and cause gas engine to slow down to idle
speed. If pilot valve does not unload as tank pressure approaches 130 P.S.I.G., slowly turn top end
setting (4) counterclockwise until pilot starts to unload prematurely (at 100 P.S.I.G.), turn top end
setting (4) clockwise in 1/4 turn increments, tap down on the internal rod at toggle attachment and
repeat until desired top end setting is reached. If pilot valve begins to rifle (sputter), fine tune
differential setting (2) 1/16 turn in either direction until rifling stops. After fine tuning, secure setting
by turning locknuts (1 & 3) clockwise until tight. Hold setting (2 & 4) in place while turning locknuts to
secure.
SCHMIDT BELT-TIGHTENING DEVICE
(FOR GAS UNITS ONLY)
NOTE: Should only be performed by ROLAIR factory authorized personnel.
To tighten belt tension, proceed as follows:
1.
Loosen locknuts for engine hold-down bolts only until washers beneath spin freely.
2.
Rotate 1/2” adjusting bolt clockwise until desired tension is reached. (See Figure 4).
3.
Retighten locknuts to secure engine.
DRIVE PULLEYS
Drive pulleys must be properly aligned and drive belt
tension set to specification. Improper pulley alignment and belt
tension can cause motor overloading, excessive vibration and
premature belt and/or bearing failure. (See Figure 5).
GASOLINE ENGINE RPM SETTINGS
Model
Top RPM
Idle RPM
Pump RPM
4090 Series
2950
1900
1025
1040 & 2040 Series
2775
1900
1175
6590 Series
3150
1900
1125
8422 & 8230 Series
3000
1900
900
NOTE: Engine RPM’s (High – Low Settings) are factory set for maximum efficiency. Adjusting RPM’s above factory specification
will void the warranty.
TROUBLESHOOTING
