Honda CRF250R User Manual

84 Servicing Your Honda
Piston/Piston Rings/Piston Pin
1. Clean any gasket material off cylinder head.
2. Install the cam chain guide (1) and fit the cam
chain guide tabs (2) in the cylinder cut-outs
(3).
Push the guide until it bottoms in the crankcase
guide groove.
3. Install the dowel pins (4) and a new cylinder
head gasket (5).
NOTICE
Do not let the dowel pins fall into the crankcase.
4. Route the cam chain through the cylinder head
and install the cylinder head (6).
NOTICE
Do not damage mating surfaces when installing
the cylinder head.
5. Apply engine oil to all cylinder head B bolt
threads and seating surface.
Install the washers and cylinder head B bolts (7).
Install the cylinder bolt (8) and cylinder head A
bolts (9).
6. Tighten the washers and cylinder head B bolts
to the specified torque in a crisscross pattern in
two or three steps:
33 lbf·ft (45 N·m, 4.6 kgf·m)
NOTICE
Do not let the washers fall into the crankcase.
7. Tighten the cylinder bolt and cylinder head A
bolts to the specified torque:
7 lbf·ft (10 N·m, 1.0 kgf·m)
Cylinder Head Installation
(1) cam chain guide (3) cylinder cut-outs
(2) cam chain guide tabs
(1)
(2)
(3)
(4) dowel pins
(5) cylinder head gasket (new)
(5)
(4)
(6) cylinder head
(7) washers and cylinder head B bolts
(8) cylinder bolt
(9) cylinder head A bolts
(7)
(7)
(6)
(8)
(9)

Honda CRF250R Specifications

General

Engine Type	Liquid-cooled single-cylinder four-stroke
Displacement	249cc
Bore x Stroke	79.0mm x 50.9mm
Compression Ratio	13.9:1
Starter	Electric
Transmission	Close-ratio 5-speed
Final Drive	Chain
Front Brake	Single 260mm disc with twin-piston caliper
Rear Brake	Single 240mm disc
Front Tire	80/100-21
Rear Tire	100/90-19
Wheelbase	58.3 inches
Seat Height	37.8 inches
Ground Clearance	13.1 inches
Fuel Capacity	1.7 gallons
Valve Train	Unicam OHC, four-valve
Induction	Programmed Fuel Injection (PGM-FI)
Throttle Bore	44mm
Ignition	Full transistorized ignition
Front Suspension	49mm inverted Showa coil-spring fork with rebound and compression damping adjustability; 12.2 inches travel
Rear Suspension	Pro-Link Showa single shock with adjustable spring preload, rebound and compression damping; 12.4 inches travel
Rake	27.2°
Trail	115mm (4.5 inches)