all spark plugs, air cleaner, radiator cap and oil filler cap.
the piston of the cylinder being tested to the TDC position on the
compression stroke (make sure both valves are closed).
line from air compressor to quick-disconnect coupling on the side
of the regulator. Caution: DO
NOT connect compressor to ship hose.
Be sure line pressure on compressor doesn’t exceed 300
spark plug adaptor into the quick-disconnect coupling located on
the end of the whip hose of the regulator.
The spark plug adaptor is not yet placed in the spark plug
hole of the cylinder head.
the spark plug adaptor connected to the whip hose, air should now
be flowing through the regulator.
Adjust the INPUT pressure on the regulator (left-hand
gauge) to any of the input pressures covered on the comparison
chart (70, 80, 90, or 100 psi).
You should use an input pressure that is AT LEAST 10 psi
less than the pressure on your compressor.
If your compressor will only hold a pressure of 90 psi,
then set the input pressure on your left-hand gauge at 80 psi.
It is important that you maintain the same exact input
pressure reading on all cylinders tested.
spark plug adaptor from whip hose of regulator and install it into
the cylinder to be tested.
With the adaptor removed from the whip, the input
pressure may or may not remain where you set it – this is normal
because the regulator only functions properly with air flow.
the whip hose to the spark plug adaptor that is now in the spark
the necessary adjustments to the regulator to maintain the proper
input pressure (left-hand gauge).
RELATIVE PRESSURE of the cylinder being tested is automatically
indicated on the right-hand gauge.
If you are using 80 psi input pressure and your right-hand
gauge reads 74.4 psi, by checking the comparison chart, you will
find that you have a 7% leakage.
leakage and repeat test on remaining cylinders.
Due to running clearances and normal wear, you can’t
expect a cylinder to have zero leakage. However, all cylinders should read within a few percentages of
one another. A difference
of 5 or 6 psi between cylinders is okay, but if you get out to 10 or
more psi difference between cylinders, you should find out what is
causing the problem and correct it.
For Escaping Air: Air escaping from the
crankcase or breather is an indication of leakage past the rings.
Air escaping out of
headers indicates a defective exhaust valve or seat. Air escaping from
carburetor or intake manifold indicates a defective intake valve
or seat. If air bubbles are
present in the radiator or coolant, check for a leaking head
gasket or a cracked head or block.