Hisun HS700UTV-4 Maintenance Handbook page 62

a. Turn the drive sprocket by hand and shift the transmission into top gear with the shift
pedal.
b. Mount a holding tool or equivalent onto the drive sprocket. Use a wooden block and clamp
to hold the holding tool so it cannot move when the combustion chamber becomes
pressurized.
c. Check that the TDC marks are still aligned as described in Step7, If not, turn the
crankshaft as required, then relock the holding tool in position.
9. Remove the radiator cap and the oil filler cap.
10. Perform a cylinder leak down test by applying air pressure to the combustion chamber.
Follow the manufacturer's instructions while reading the percent of leakage on the gauge.
Listen for air leaking while noting the following:
Because of play in the transmission gears, it is unlikely the
engine will stay at TDC on the first try If the crankshaft
turns, reposition the countershaft slightly and then relock it
in position with the holding tool. After several attempts, you
will get a feel of the transmission play and know what
direction the countershaft should be turned and locked.
If a large amount of air escapes from the exhaust pipe or
through the throttle, the air is leaking through on open
valve, Check the index mark to make sure the engine is at
TDC on the compression stroke, If the engine is remaining
at TDC but there is still a large amount of air escaping from
the engine, the crankshaft is off one revolution. Turn the
engine 360°and realign the TDC mark as described in Step 7,
then relock it as described in Step8.
a. Air leaking through the exhaust pipe indicates a leaking exhaust valve.
b. Air leaking through the throttle indicates a leaking intake valve.
c. Air leaking through both the intake and exhaust valves indicates the engine is not set at
TDC on its compression stroke.
d. Air leaking through the coolant filler neck indicates a leaking cylinder head gasket or a
cracked cylinder head or cylinder liner.
e. Air leaking through the oil filler hole indicates the rings are not sealing properly in the
bore.
11. If the cylinder leak down is 10 percent or higher, further service is required.
12. Disconnect the test equipment and install all the parts previously removed.
GENERAL INFORMATION
NOTE
NOTE
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