Yamaha BEARTRACKER YFM250XC, Service Manual

Page: 381 / 398

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SPEC
MAINTENANCE SPECIFICATIONS
MAINTENANCE SPECIFICATIONS
ENGINE
Item Standard Limit
Cylinder head:
Warp limit ---- 0.03 mm
(0.001 in)
Measuring point Lines indicate straightedge
measurement.
Piston:
Piston to cylinder clearance 0.04 ~ 0.06 mm
(0.0016 ~ 0.0024 in) 0.15 mm
(0.0059 in)
Piston size “D” 70.92 ~ 70.97 mm
(2.792 ~ 2.794 in) ----
Measuring point “H” 4.0 mm (0.16 in) from bottom line
of piston skirt ----
Oversize 2nd 71.5 mm (2.81 in) ----
Oversize 4th 72 mm (2.83 in) ----
Piston off-set 0.5 mm (0.02 in) ----
Piston off-set direction Intake side ----
Piston pin bore inside diameter 16.002 ~ 16.013 mm
(0.6300 ~ 0.6304 in) ----
Piston pin outside diameter 15.991 ~ 16.000 mm
(0.6296 ~ 0.6299 in) ----
Lubrication system:
Oil filter type Wire mesh ----
Oil pump type Trochoid type ----
Tip clearance “A” or “B” 0.15 mm (0.006 in) 0.20 mm
(0.008 in)
Side clearance 0.04 ~ 0.09 mm
(0.002 ~ 0.004 in) 0.09 mm
(0.004 in)
Bypass valve setting pressure 80 ~ 120 kPa
(0.8 ~ 1.2 kg/cm
2
, 11 ~ 17 psi)
----
Oil pressure (hot) 52 kPa (0.52 kg/cm², 7.5 psi) at
7,500 r/min ----
Pressure check location Element cover ----
*
H
D