Yamaha YZ250 2022, Owner'S Service Manual

Page: 42 / 274

ENGINE SPECIFICATIONS
2-3
2nd ring
End gap limit 0.95 mm (0.0374 in)
Ring side clearance 0.030–0.065 mm (0.0012–0.0026 in)
Side clearance limit 0.100 mm (0.0039 in)
Crankshaft
Crank assembly width 59.95–60.00 mm (2.360–2.362 in)
Runout limit 0.050 mm (0.0020 in)
Clutch
Clutch type Wet, multiple-disc
Clutch lever free play 7.0–12.0 mm (0.28–0.47 in)
Friction plate thickness 2.90–3.10 mm (0.114–0.122 in)
Wear limit 2.80 mm (0.110 in)
Plate quantity 8 pcs
Clutch plate thickness 1.50–1.70 mm (0.059–0.067 in)
Plate quantity 7 pcs
Warpage limit 0.20 mm (0.008 in)
Clutch spring free length 50.00 mm (1.97 in)
Clutch spring free length limit 48.00 mm (1.89 in)
Push rod bending limit 0.30 mm (0.012 in)
Drivetrain
Primary reduction ratio 3.000 (63/21)
Transmission type Constant mesh 5-speed
Gear ratio
1st 1.929 (27/14)
2nd 1.533 (23/15)
3rd 1.278 (23/18)
4th 1.091 (24/22)
5th 0.952 (20/21)
Main axle runout limit 0.01 mm (0.0004 in)
Drive axle runout limit 0.01 mm (0.0004 in)
Secondary reduction ratio 3.571 (50/14)
Final drive Chain
Air filter
Air filter element Wet element
Air filter oil grade Yamaha foam air filter oil or other quality foam
air filter oil
Carburetor
Type

quantity PWK38

1
ID mark 1P87 53
Main jet #178
Main air jet #200
Jet needle N3-EW-2
Needle jet 2.9(#6)
Cutaway #7
Pilot outlet 0.8
Pilot jet #50
Bypass 1 1.5
Air screw turns out 1-1/4
Valve seat size 3.8
Starter jet 1 #85
Power Jet #50