ENGINE INSPECTION
5-1
ENGINE INSPECTION
MEASURING THE COMPRESSION
PRESSURE
TIP
Insufficient compression pressure will result in a
loss of performance.
1. Measure:
• Valve clearance
Out of specification
→
Adjust.
Refer to “CHECKING THE ENGINE COOL-
ING INLET DUCT (YUM1A/YUM2A)” on
page 3-4.
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Remove:
• Seat frames (driver and passenger)
Refer to “GENERAL CHASSIS (1)” on page
4-1.
• Drive belt
Refer to “REPLACING THE DRIVE BELT
(YUM1A/YUM2A)” on page 3-8.
4. Disconnect:
• Spark plug cap
5. Remove:
• Spark plug
NOTICE
Before removing the spark plug, use com-
pressed air to blow away any dirt accumulat-
ed in the spark plug well to prevent it from
falling into the cylinder.
6. Install:
• Extension “1”
• Compression gauge “2”
7. Measure:
• Compression pressure
Out of specification
→
Refer to steps (b) and
(c).
a. Crank the engine by fully pressing the ac-
celerator pedal until the reading on the
compression gauge stabilizes.
WARNING
To prevent sparking, ground the spark plug
lead before cranking the engine.
b. If the compression pressure is above the
maximum specification, check the cylinder
head, valve surfaces and piston crown for
carbon deposits.
Carbon deposits
→
Eliminate.
c. If the compression pressure is below the
minimum specification, pour a teaspoonful
of engine oil into the spark plug bore and
measure again.
Refer to the following table.
8. Install:
• Spark plug
TIP
Before installing the spark plug, clean the spark
plug and gasket surface.
9. Connect:
• Spark plug cap
10.Install:
• Drive belt
Refer to “REPLACING THE DRIVE BELT
(YUM1A/YUM2A)” on page 3-8.
• Seat frames (driver and passenger)
Refer to “GENERAL CHASSIS (1)” on page
4-1.
Extension
90890-04082
Compression gauge
90890-03081
Engine compression tester
YU-33223
2
1
Compression pressure
700–900 kPa (7.0–9.0 kgf/cm²,
102–131 psi)
Compression pressure (with oil applied into the
cylinder)
Reading
Diagnosis
Higher than without oil
Piston ring(s) wear or
damage
→
Repair.
Same as without oil
Piston, valves, cylinder
head gasket, or piston
ring(s) possibly defec-
tive
→
Repair.
T
R
.
.
Spark plug
20 N·m (2.0 kgf·m, 15 lb·ft)
Summary of Contents for UMAX
Page 1: ...SERVICE MANUAL UTILITY VEHICLE J0F F8197 E1 YUM1A YUM2A YUM2E LIT 19616 A0 37...
Page 2: ......
Page 6: ......
Page 8: ......
Page 25: ...GENERAL SPECIFICATIONS 2 2 1174 kg 2589 lb YUM2E Hill claiming ability 20 YUM1A 15 YUM2A YUM2E...
Page 33: ...ELECTRICAL SPECIFICATIONS YUM1A YUM2A 2 10 USB fuse 5 A...
Page 43: ...TIGHTENING TORQUES 2 20...
Page 46: ...CABLE ROUTING 2 23 YUM1A Front and rear A B C 1 1 1 1 2 3 4 3 4 1 2 3 4 5 6...
Page 48: ...CABLE ROUTING 2 25 YUM1A Left side A B D C 1 2 3 4 4 4 4 5 6 7 8 9...
Page 50: ...CABLE ROUTING 2 27 YUM1A Brake and throttle cables A B 1 3 2 3 1 2 2 4 5...
Page 52: ...CABLE ROUTING 2 29 YUM1A Shift cables 1 2 3 1 2 4 1 2...
Page 56: ...CABLE ROUTING 2 33 YUM2A Front and rear A B C D 1 1 1 1 1 2 2 3 3 4 4 3 4 5 6 7...
Page 58: ...CABLE ROUTING 2 35 YUM2A Left side A B C D 1 2 3 4 4 4 4 6 7 8 9 10 5...
Page 60: ...CABLE ROUTING 2 37 YUM2A Brake throttle and shift cables A A B C D 1 1 2 3 3 4 5 4 5 6 6 7 8 9...
Page 62: ...CABLE ROUTING 2 39 YUM2E Frame top view A A B 1 2 3 4 5 6 7 C D E E 6 6 6 8 9 10 11 12...
Page 64: ...CABLE ROUTING 2 41 YUM2E Front and rear 1 1 2 3 4 3 A...
Page 66: ...CABLE ROUTING 2 43 YUM2E Left side B 2 1 3 4 5 6 7 8 9 10 11 A 9...
Page 68: ...CABLE ROUTING 2 45 YUM2E Brake cable A A B C 1 2 4 3...
Page 70: ...CABLE ROUTING 2 47...
Page 73: ......
Page 96: ...4 YEAR CHECKS 3 23...
Page 99: ......
Page 134: ...FRONT SUSPENSION COMPONENTS 4 35 4 3 1 2 5 a...
Page 138: ...REAR SUSPENSION COMPONENTS 4 39...
Page 174: ...CRANKSHAFT AND PISTON 5 35...
Page 196: ...TRANSMISSION YUM1A YUM2A 7 13 Refer to CHECKING THE SHIFT LEVER YUM1A YUM2A on page 3 8...
Page 202: ...TRACTION MOTOR YUM2E 7 19...
Page 205: ......
Page 217: ...CHARGING SYSTEM YUM1A YUM2A 8 12...
Page 223: ...LIGHTING SYSTEM YUM1A YUM2A 8 18...
Page 227: ...LIGHTING SYSTEM YUM2E 8 22...
Page 233: ...SIGNALING SYSTEM YUM1A YUM2A 8 28...
Page 243: ...FUEL INJECTION SYSTEM YUM1A YUM2A 8 38...
Page 247: ...FUEL PUMP SYSTEM YUM1A YUM2A 8 42...
Page 284: ...ELECTRICAL COMPONENTS YUM2E 8 79...
Page 313: ...PC GENIUS GOLF CAR PROGRAMMING SYSTEM YUM2E 9 28...
Page 315: ......
Page 316: ......