Yamaha MX250 - Maintenance Specifications; Engine

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SPECIFICATIONS
MAINTENANCE SPECIFICATIONS
MAINTENANCE SPECIFICATIONS
ENGINE
Piston:
Piston-to-cylinder clearance 0.033–0.047 mm (0.0012–0.0018 in)
Limit 0.06 mm (0.0024 in)
Piston diameter 79.96–79.98 mm (3.1480–3.1488 in)
Limit 79.91 mm (3.1461 in)
Measuring point (from piston
skirt bottom)
10.0 mm (0.3937 in)
Oversize 1st 80.25 mm (3.1594 in)
2nd 80.50 mm (3.1692 in)
Piston pin hole inside diameter 19.004–19.015 mm (0.7481–0.7486 in)
Limit 19.045 mm (0.7498 in)
Piston pin:
Piston pin diameter 18.995–19.000 mm (0.7478–0.7480 in)
Limit 18.975 mm (0.7470 in)
Piston ring:
Top ring
Type Barrel
Dimensions 1.2  2.9 mm (0.0472  0.1141 in)
End gap (installed) 0.20–0.35 mm (0.0079–0.0138 in)
Limit 0.60 mm (0.0236 in)
Side clearance 0.03–0.05 mm (0.0011–0.0019 in)
Limit 0.10 mm (0.0039 in)
2nd ring
Type Taper
Dimensions 1.2  3.2 mm (0.0472  0.1260 in)
End gap (installed) 0.20–0.35 mm (0.0079–0.0138 in)
Limit 0.70 mm (0.0275 in)
Side clearance 0.02–0.04 mm (0.0007–0.0015 in)
Limit 0.10 mm (0.0039 in)
Oil ring
Type 3-piece type
Dimensions 2.5  2.5 mm (0.0984  0.0984 in)
End gap (installed) 0.20–0.70 mm (0.0079–0.0276 in)
Cylinder head:
Warpage limit 0.05 mm (0.002 in)
Cylinder:
Bore 80.000–80.020 mm (3.1496–3.1503 in)