Beta RR 125 LC Manual page 13

TIP
The ignition timing is not adjustable.
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4. Remove:
• Digital tachometer
• Timing light
5. Install:
• Timing mark accessing screw
(along with the O-ring
EAS20710
MEASURING THE COMPRESSION
PRESSURE
TIP
Insufficient compression pressure will result in a
loss of performance.
1. Measure:
2. Valve clearance
Out of specification → Adjust.
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Disconnect:
• Spark plug cap
4. Remove:
• Spark plug
ECA13330
NOTICE
Before removing the spark plug, blow away
any dirt accumulated in the spark plug well
with compressed air to prevent it from falling
into the cylinder.
5. Install:
• Extension "1"
• Compression gauge "2"
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New )
LLL
2
6. Measure:
• Compression pressure
Out of specification → Refer to steps (c) and
(d).
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a. Set the main switch to "ON".
b. With the throttle wide open, crank the engine
until the reading on the compression gauge
stabilizes.
c. If the compression pressure is above the
maximum specification, check the cylinder
head, valve surfaces and piston crown for
carbon deposits.
Carbon deposits → Eliminate.
d. If the compression pressure is below the min-
imum specification, pour a teaspoonful of en-
gine oil into the spark plug bore and measure
again.
Refer to the following table.
Compression pressure (with oil applied into
the cylinder)
Reading
Higher than without
oil
Same as without oil
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7. Remove:
• Extension
• Compression gauge
1
Standard compression pressure
(at sea level)
550 kPa/600 r/min (5.5
kgf/cm²/600 r/min, 78.2 psi/600
r/min)
Minimum–maximum
480–620 kPa (4.8–6.2 kgf/cm²,
68.3–88.2 psi)
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Diagnosis
Piston ring(s) wear or
damage → Repair.
Piston, valves, cylin-
der head gasket or
piston ring(s) possi-
bly defective → Re-
pair.
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ENGINE
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