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SYSTEM CONTROLS
(continued)
(8) PILOT-UNLOADER VALVE
A pilot-unloader valve is used on all gas-powered units and can be used on electric air compressors to operate in a
continuous manner. When the storage tank reaches the top pressure setting of the pilot valve, the air being compressed is discharged to
atmosphere instead of into the storage tank. When the tank pressure drops to the low pressure setting of the pilot valve, the compressed air will
be redirected to the air tank. Do not attempt to replace the pilot valve without first draining the tank pressure completely. See Figure 3 for
adjustment and fine-tuning instructions. Do not adjust above the following factory recommendations.
Classification
Pressure Setting
Direct Drive Compressor
105-130 PSI
I-Stage Compressor
110-135 PSI
II-Stage Compressor
130-150 PSI
(9) SIGHT GAUGE/DIPSTICK
Prior to daily operation, make a habit of checking the oil level of the compressor pump and engine (if compressor is
gas powered). Every direct-drive hand-carry air compressor has a dipstick to help check and maintain the proper oil level. The dipstick also functions
as a crankcase vent. Never operate a direct-drive unit without the factory-supplied dipstick. Our belt-driven air compressors are equipped with a
sight gauge to make the daily task of checking the oil level easier. Always maintain the oil level to read 2/3 full on the sight gauge.
(10) CHECK VALVE
Every ROLAIR
air compressor is built with a check valve to seal off and maintain tank pressure after the top end pressure setting
of pilot valve or pressure switch is reached. The check valve works in conjunction with the pressure switch relief valve to provide a loadless start
for the compressor system. A quick burst of air escaping from the pressure switch relief valve after an electric unit reaches top end indicates the
check valve is working properly. If the compressor has a mysterious leak after stopping that cannot be traced elsewhere, the check valve may
require servicing/replacing.
(11) BREATHER/OIL FILL PLUG
All reciprocating air compressor pumps are built with a crankcase vent to relieve the pressure that is created by the
downward movement of the piston in the pump cylinder. Our direct-drive air compressors vent the crankcase pressure through special ports in the
dipstick. Our belt-drive units vent through the oil-fill plug. Never operate the air compressor without the dipstick or oil-fill plug.
(12) AUTOMATIC-IDLE CONTROL
Every ROLAIR
gas-powered air compressor is built with an engine idle control kit that automatically decreases
the engine speed when the top end pressure setting of the pilot unloader valve is reached. The top RPM setting of the engine is factory set for
maximum performance and service life. Do not alter the factory top RPM setting. The engine idle speed is factory set and controlled by a black
plastic Philips head screw on the carburetor. A slight increase to the idle speed setting may be required when operating in colder temperatures.
Turn screw clockwise in 1/4 turn increments to increase the idle speed. If the idle speed setting is too low, premature fouling of spark plug will
occur.
(13) COLD-START VALVE
Most ROLAIR direct-drive air compressors are built with an automatic cold-start valve that allows the motor/pump to
warm up before being subjected to tank pressure. Our belt-driven portable units have a manual drain valve installed on the pump aftercooler to
assist with cold weather starting. Open drain valve and allow the motor and pump to run
unloaded
for a minute to warm up. Close the drain and
repeat the procedure if the motor or engine continue to struggle.
(14) SCHMIDT BELT-TIGHTENING DEVICE (FOR GAS UNITS ONLY)
Every ROLAIR gas-powered belt-driven portable air compressor has a unique
system for maintaining proper belt tension. Simply loosen the 1/2” locknuts (only until washers beneath spin freely) that secure the engine and
rotate the fine thread bolt located on the wheel end of the base plate clockwise until the desired belt tension is achieved. (See drawing in section
on operating instructions for proper tension) Re-tighten 1/2” locknuts to secure engine and maintain desired belt tension setting.
(15) VIBRATION DAMPENER(S)
The rubber pads installed beneath every portable ROLAIR tank assembly are very important to the proper operation
of the air compressor. They provide protection from vibration that left unchecked could cause damage to many system components.
(16) ENGINE KILL SWITCH
A kill switch is installed to easily stop the engine. Do not attempt to move the throttle lever (as described in the Honda
owner’s manual) when stopping the engine. The engine throttle lever is factory set and locked down at a top RPM setting that will provide maximum
performance and service life for the complete air compressor system. The kill switch must be moved to the “On” position prior to pulling the recoil
rope assembly to start the engine.
(17) ENGINE CHOKE
Moving the choke lever completely to the left (closed position) will help start a cold engine. Also see instructions for cold-start
valve (Item #13). After start up, the choke lever must be moved completely to the right (open position) for the engine to operate properly. Fouling
of spark plug and excessive internal carbon build up will occur if engine is operated with choke lever even partially closed.
(18) FUEL SHUT-OFF VALVE
T
he fuel shut-off valve should only be moved to the “Open” position (completely to the right) when the engine is being
operated. Always stop the flow of fuel by moving the shut-off valve completely to the left when the engine is not being operated. Do not move or
transport the air compressor with the fuel valve in the open position.
