Harbor Freight Tools COMPRESSION TESTER 92720 - Manual (Page 5)

SKU 92720 For technical questions please call 1-800-444-3353 PAGE 5
9. WARNING! The warnings, precautions, and instructions discussed in this
manual cannot cover all possible conditions and situations that may occur. The
operator must understand that common sense and caution are factors, which
cannot be built into this product, but must be supplied by the operator.
OPERATING INSTRUCTIONS
2. The Compression Tester features an Adapter Fitting (2) with its Rubber Cone that
may be used on
all types of spark plug holes and a Hose Fitting (4) that may be
used for 14mm and 18mm spark plug holes. (See Figure A.)
3. To perform a typical compression test, prepare the engine for compression test-
ing by starting the engine and allowing it to warm up to its normal operating
temperature. Then, switch off the ignition. WARNING! Avoid carbon monoxide
poisoning! Never run a gasoline engine in an enclosed garage or other
contained area.
4. Once the engine has been turned off, disconnect both coil wires from the coil of
the engine, and remove all of the spark plugs. Note: Insulate coil wires or route
them away from each other and all metal surfaces. Make note of which spark
plug wires go to each spark plug locations. (See Figures B and C, next page.)
GAUGE
(1)
ADAPTER FITTING
(2)
HOSE
(3)
HOSE FITTING
(4)
RUBBER CONE
AIR RELEASE BUTTON
FIGURE A
1. NOTE: Performing a compression test requires the work of two individuals; one
person to operate the vehicle’s ignition switch while the other person operates
the Compression Tester.