2016 YAMAHA YZ250F dimensions

GENERAL SPECIFICATIONS
2-1
EAS1SM9050
GENERAL SPECIFICATIONS
Model
Model 1SM9, 1SMD (USA) (CAN)
1SMA, 1SMF (EUR)
1SMB, 1SMG (JPN)
1SMC, 1SMH (AUS) (NZL) (ZAF)
Dimensions
Overall length 2165 mm (85.2 in)
Overall width 825 mm (32.5 in)
Overall height 1280 mm (50.4 in)
Seat height 965 mm (38.0 in)
Wheelbase 1475 mm (58.1 in)
Ground clearance 325 mm (12.80 in)
Weight
Curb weight 105 kg (231 lb)

ENGINE SPECIFICATIONS
2-3
Cylinder head
Combustion chamber volume 12.07–12.87 cm3 (0.74–0.79 cu.in)
Warpage limit 0.05 mm (0.0020 in)
Camshaft
Drive system Chain drive (left)
Camshaft cap inside diameter 22.000–22.021 mm (0.8661–0.8670 in)
Camshaft journal diameter 21.959–21.972 mm (0.8645–0.8650 in)
Camshaft-journal-to-camshaft-cap clearance 0.028–0.062 mm (0.0011–0.0024 in)
Camshaft lobe dimensions
Lobe height (Intake) 31.730–31.830 mm (1.2492–1.2531 in)
Limit 31.630 mm (1.2453 in)
Base circle diameter (Intake) 22.450–22.550 mm (0.8839–0.8878 in)
Limit 22.350 mm (0.8799 in)
Lobe height (Exhaust) 33.370–33.470 mm (1.3138–1.3177 in)
Limit 33.270 mm (1.3098 in)
Base circle diameter (Exhaust) 25.211–25.311 mm (0.9926–0.9965 in)
Limit 25.111 mm (0.9886 in)
Camshaft runout limit 0.030 mm (0.0012 in)
Timing chain
Tensioning system Automatic
Valve, valve seat, valve guide
Valve clearance (cold)
Intake 0.12–0.19 mm (0.0047–0.0075 in)
Exhaust 0.17–0.24 mm (0.0067–0.0094 in)
Valve dimensions
Valve head diameter (intake) 30.90–31.10 mm (1.2165–1.2244 in)
Valve head diameter (exhaust) 24.90–25.10 mm (0.9803–0.9882 in)
Valve face width (intake) 1.697 mm (0.0668 in)
Valve face width (exhaust) 1.909 mm (0.0752 in)
Valve seat contact width (intake) 0.90–1.10 mm (0.0354–0.0433 in)
Valve seat contact width (exhaust) 0.90–1.10 mm (0.0354–0.0433 in)
Valve margin thickness (intake) 1.20 mm (0.0472 in)
Valve margin thickness (exhaust) 0.85 mm (0.0335 in)
Valve stem diameter (intake) 4.975–4.990 mm (0.1959–0.1965 in)
Limit 4.945 mm (0.1947 in)
Valve stem diameter (exhaust) 4.460–4.475 mm (0.1756–0.1762 in)
Limit 4.430 mm (0.1744 in)
Valve guide inside diameter (intake) 5.000–5.012 mm (0.1969–0.1973 in)
Limit 5.050 mm (0.1988 in)
Valve guide inside diameter (exhaust) 4.500–4.512 mm (0.1772–0.1776 in)
Limit 4.550 mm (0.1791 in)
Valve-stem-to-valve-guide clearance (intake) 0.010–0.037 mm (0.0004–0.0015 in)
Limit 0.080 mm (0.0032 in)
Valve-stem-to-valve-guide clearance (exhaust) 0.025–0.052 mm (0.0010–0.0020 in)
Limit 0.100 mm (0.0039 in)
Valve stem runout 0.010 mm (0.0004 in)

ENGINE SPECIFICATIONS
2-4
Valve spring
Free length (intake) 36.69 mm (1.44 in)
Limit 34.85 mm (1.37 in)
Free length (exhaust) 34.86 mm (1.37 in)
Limit 33.11 mm (1.30 in)
Installed length (intake) 31.40 mm (1.24 in)
Installed length (exhaust) 28.50 mm (1.12 in)
Spring rate K1 (intake) 29.65 N/mm (2.99 kgf/mm, 169.30 lbf/in)
Spring rate K2 (intake) 39.31 N/mm (4.01 kgf/mm, 222.46 lbf/in)
Spring rate K1 (exhaust) 23.11 N/mm (2.36 kgf/mm, 131.96 lbf/in)
Spring rate K2 (exhaust) 30.88 N/mm (3.15 kgf/mm, 176.32 lbf/in)
Installed compression spring force (intake) 146.00–168.00 N (14.89–17.13 kgf,
32.82–37.77 lbf)
Installed compression spring force (exhaust) 137.00–157.00 N (13.97–16.01 kgf,
30.80–35.29 lbf)
Spring tilt (intake) 2.5 °/1.6 mm (2.5 °/0.06 in)
Spring tilt (exhaust) 2.5 °/1.5 mm (2.5 °/0.06 in)
Winding direction (intake) Clockwise
Winding direction (exhaust) Clockwise
Cylinder
Bore 77.000–77.010 mm (3.0315–3.0319 in)
Taper limit 0.050 mm (0.0020 in)
Out of round limit 0.050 mm (0.0020 in)
Piston
Piston-to-cylinder clearance 0.030–0.055 mm (0.0012–0.0022 in)
Limit 0.15 mm (0.006 in)
Diameter 76.955–76.970 mm (3.0297–3.0303 in)
Measuring point (from piston skirt bottom) 4.0 mm (0.16 in)
Offset 0.00 mm (0.0000 in)
Piston pin bore inside diameter 16.002–16.013 mm (0.6300–0.6304 in)
Limit 16.043 mm (0.6316 in)
Piston pin outside diameter 15.991–16.000 mm (0.6296–0.6299 in)
Limit 15.971 mm (0.6288 in)
Piston ring
Top ring
Ring type Barrel
Dimensions (B  T) 0.90  2.70 mm (0.04  0.11 in)
End gap (installed) 0.15–0.25 mm (0.0059–0.0098 in)
Limit 0.50 mm (0.0197 in)
Ring side clearance 0.030–0.065 mm (0.0012–0.0026 in)
Limit 0.120 mm (0.0047 in)
Oil ring
Dimensions (B  T) 1.50  2.25 mm (0.06  0.89 in)
End gap (installed) 0.10–0.35 mm (0.0039–0.0138 in)
Crankshaft
Crank assembly width 55.95–56.00 mm (2.203–2.205 in)
Runout limit 0.030 mm (0.0012 in)
Big end side clearance 0.110–0.690 mm (0.0043–0.0272 in)

HANDLEBAR
4-34
3. Tighten:
• Lower handlebar holder nut4. Install:
• Handlebar grip “1”
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Slightly coat the handlebar left end with a
rubber adhesive.
b. Install the handlebar grip on the handlebar
by pressing the grip from the left side.
c. Wipe off any excess adhesive with a clean
cloth.
EWA13120
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
TIP
Install the handlebar grip to the handlebar so
that the line “a” between the two arrow marks
faces straight upward.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
5. Install:
• Handlebar grip “1”
• Handlebar grip “2”
• Handlebar grip “3”
•Clamp “4”
TIP
• The engine stop switch, the clutch lever, and
the clutch lever holder should be installed ac-
cording to the dimensions shown.
• Pass the engine stop switch lead through the
middle of the clutch lever holder. Lower handlebar holder nut
40 Nm (4.0 m·kgf, 29 ft·lbf)
3
4
T R..
Engine stop switch screw
0.5 Nm (0.05 m·kgf, 0.36 ft·lbf)
Clutch lever holder bolt
5 Nm (0.5 m·kgf, 3.6 ft·lbf)
T R..

CAMSHAFT
5-14
EAS1SM9207CHECKING THE CAMSHAFT
1. Check:
• Camshaft lobes
Blue discoloration/pitting/scratches  Re-
place the camshaft.
2. Measure:
• Camshaft lobe dimensions “A” and “B”
Out of specification  Replace the cam-
shaft.3. Measure:
• Camshaft runout
Out of specification  Replace.
4. Measure:
• Camshaft-journal-to-camshaft-cap clear-
ance
Out of specification  Measure the cam-
shaft journal diameter.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Install the camshaft into the cylinder head.
b. Position a strip of Plastigauge® “1” onto the
camshaft journal as shown. Camshaft lobe dimensions
Lobe height (Intake)
31.730–31.830 mm (1.2492–
1.2531 in)
Limit
31.630 mm (1.2453 in)
Base circle diameter (Intake)
22.450–22.550 mm (0.8839–
0.8878 in)
Limit
22.350 mm (0.8799 in)
Lobe height (Exhaust)
33.370–33.470 mm (1.3138–
1.3177 in)
Limit
33.270 mm (1.3098 in)
Base circle diameter (Exhaust)
25.211–25.311 mm (0.9926–
0.9965 in)
Limit
25.111 mm (0.9886 in)
1
2
3
Camshaft runout limit
0.030 mm (0.0012 in)
Camshaft-journal-to-camshaft-
cap clearance
0.028–0.062 mm (0.0011–0.0024
in)
1