Yamaha BEARTRACKER YFM250XC, Service Manual

Page: 73 / 398

3 - 19
INSP
ADJ
COMPRESSION PRESSURE MEASUREMENT/
ENGINE OIL LEVEL INSPECTION
● If pressure falls below the minimum level:
1) Squirt a few drops of oil into the affected
cylinder.
2) Measure the compression again.
● Remove the compression gauge.
**********************************
4.Install:
●
Spark plug
Refer to “SPARK PLUG INSPECTION” sec-
tion.
Compression pressure
(with oil introduced into cylinder)
Reading Diagnosis
Higher than with-
out oil Worn or damaged cyl-
inder or rings
Same as without
oil
Defective ring(s),
valves, cylinder head
gasket.
Above maximum
level
Inspect cylinder head,
valve surface, or pis-
ton crown for carbon
deposit.
T
R
.
.
Spark plug:
17.5 Nm (1.75 m • kg, 12.5 ft • lb)
ENGINE OIL LEVEL INSPECTION
CAUTION:
●
Do not add any chemical additives.
Engine oil also lubricates the clutch and
additives could cause clutch slippage.
●
Do not allow foreign material to enter the
crankcase.
1.Place the machine on a level place.
2.Inspect:
●
Engine oil level
Oil level low
→
Add sufficient oil
**********************************
Inspection steps:
●
Warm up the engine for several minutes,
and stop it, then wait at least several min-
utes for the oil to drain back into the
crankcase.
3