Honda Crf 250 M Manual

							(4) standard position
for optional front
wheel 0 in (0 mm)
(5) top of outer tube
(6) upper fork clamp
Chassis Adjustments
Adjustments for Competition127 The following suggestions may improve a
specific concern.  Subtle changes in overall
handling may also be noted.
Rear End
If you have a problem with rear wheel traction,
raise the rear end of your motorcycle by
increasing the rear spring pre-load.  Instead of
running 3.9 in (100 mm) of sag, you can run 3.5
in (90 mm) so the rear of the bike will sit a little
higher.  This should produce more traction
because of the change to the swingarm and the
location of your motorcycle’s center of gravity.
If you have a problem with the steering head
shaking when you use the front brake hard or if
your motorcycle wants to turn too quickly, lower
the rear of the motorcycle by reducing the rear
spring pre-load.  This will increase fork rake and
trail and should improve stability in a straight
line.  The effective suspension travel will be
transferred toward the firmer end of wheel travel.
Keep the race sag adjustment (page 109) in the
3.5 - 3.9 in (90 – 100 mm) range.
Fork Height/Angle
The position of the fork tubes in the clamps is
not adjustable. Align the groove in the outer tube
with the top surface of the upper fork clamp.
If you install the optional 20 inch wheel, align
the top of the fork tube with the top of the upper
fork clamp.
Standard Position
The standard position (1) aligns the index groove
(2) with the top of the upper clamp (3).
Standard Position For Optional Front 
Wheel
If you install the optional 20 inch wheel, align
the top of the fork tube (5) (not the top of the
fork cap) with the top of the upper fork clamp
(6).
Wheelbase
Adjusting your CRF’s wheelbase can offer subtle
changes in overall handling.  You may adjust
wheelbase by adding or removing links on the
drive chain.  If you change the wheelbase, be
sure to re-check race sag and adjust, if necessary.
In the past, a general rule was lengthen the
wheelbase to add straight line stability, shorten
the wheelbase to improve turning.  However, we
suggest you do not lengthen the wheelbase of
your CRF unless you are racing on a track with
more fast sections than normal.
As a general recommendation, keep the
wheelbase as short as possible.  This positions
the wheels closer together, improves turning
response, increase weighting (traction) on the
rear wheel, and lightens weighting on the front
wheel.
With your CRF, you will probably find that the
standard setting or a shorter wheelbase will offer
more overall benefits.
(1)(2)
(3)
(4)
(5)
(6)
(1) standard position
0.3 in (7 mm)
(2) groove
(3) upper fork clamp 
						

							Gearing
128Adjustments for Competition
You can “adjust” the power delivery of the
standard engine to suit track conditions by
changing gearing.  This allows you to utilize a
different portion of the engine’s power range at a
given throttle setting.  New gearing may provide
the change you are looking for without the need
to consider further modifications.
The portion of your engine’s power range you
use can be adjusted by changing the final drive
ratio with different sized rear sprockets.  Gearing
changes allow you to more closely match the
type of terrain and the available traction.
Normally, a change of one tooth on the rear
sprocket will be sufficient.
There is a choice of both higher and lower final
drive ratios with two optional aluminum driven
sprockets.  For muddy or sandy courses, there is
a more durable steel driven sprocket with the
standard number of teeth.  Like the optional
springs, these sprockets are listed in the Optional
Parts List section of this manual.
Unless you have the required mechanical
knowhow, tools, and an official Honda Service
Manual, sprocket changing should be done by
your Honda dealer.
Higher Gearing (less rear sprocket teeth)
• increases top speed in each gear (provided the
engine will pull the higher gearing)
• reduces frequency of shifting (wider gear
ratios) 
• reduces engine rpm at a given throttle setting
or ground speed (which may allow better rear
wheel traction on slippery or loose terrain)
However:
• the engine may not pull the higher gearing
• the spacing between gears may be too wide
• engine rpm may be too lowLower Gearing (more rear sprocket teeth)
• decrease top speed in each gear
• increases frequency of shifting (narrower gear
ratios)
• increases engine rpm at a given throttle
setting or ground speed (which may provide
more power-to-the-ground on good traction
surfaces)
However:
• spacing between gears may be too narrow
• engine rpm may be too high
Some tracks may be watered heavily prior to the
first race, then lightly or not at all during the day.
This results in a track surface that is slippery
during the first few races, then changes from
good to great and back to good and possibly ends
the day with a slick rock-hard consistency.
Ideally, your gearing should be adjusted to suit
all these conditions.
• Wet and slippery or sandy conditions: use a
higher gear (less teeth) to keep engine rpm
down, and avoid unwanted wheelspin.  The
engine may bog in certain corners so you’ll
need to slip the clutch to compensate;
downshifting may be too drastic a change in
speed.
• Average conditions: use the standard sprocket.
• Hard (but not slippery) track conditions: use
lower gearing (more teeth) to keep the engine
rpm high where the engine produces the most
power.  This may require an extra upshift on
certain sections or perhaps you can just rev it
out a bit longer.
For tight tracks, consider lower gearing to avoid
having to slip the clutch frequently.  Repeated
fanning or pulling of the clutch lever in a turn to
raise engine rpm may eventually damage the
clutch system.A gearing change may help for riding in sand,
where you want to keep the front end light so it
can float from the peak of one sand whoop to the
next.  Generally, with higher gearing, it is easier
to maintain that perfect attitude (maximum rear
wheel traction and a light front end) because you
remain in the powerband longer in each gear.
The higher gearing allows you to steer more
efficiently with throttle control and body English.
If you are riding a track with sections where you
choose to over-rev the engine temporarily rather
than shifting up, higher gearing might help.
Sometimes you have to sacrifice performance on
one section of the track to gain a better overall
time.  Your goal is the fastest overall lap time,
even if the cost is some sections where the
gearing feels wrong.
If you decide to try a gearing change, have
someone check your times with a stopwatch
(before and after the change) to get an accurate
appraisal of the change.  “Seat-of-the-pants”
feelings can’t be trusted.  Eliminating wheelspin
with a gearing change can make you feel like
you’re going slower when, in reality, you’ve
decreased your time by increasing your speed
with better traction.
These gearing recommendations should be
evaluated by considering your ability, your riding
style, and the track. 
						

							Tire Selection for Track Conditions
Adjustments for Competition129 Choosing the correct tire tread pattern and rubber
compound can affect your placing in competition.
The tires on your CRF offer a “happy medium”
for the variety of soil conditions the majority of
riders are likely to encounter.  
Experienced competitors often switch to tires
developed for specific terrain conditions.  If you
do switch, stay with the factory recommended
sizes.  Other tires may affect handling or
acceleration.  
Be aware that tire sizes (width and aspect ratio)
do vary from manufacturer to manufacturer or
even among tires made by the same
manufacturer.  Variations in tires, especially the
sidewall profile, can change the attitude of your
CRF and its handling.  Tire variations that raise
or lower the rear of your CRF have a more
significant effect on handling than variations in
front tires which, generally, don’t vary as much.
Often, you can see or feel the change in tire size.
Another way to check is to measure the rolling
circumference of the old and new tires.  A higher
profile tire will have a larger rolling
circumference.
If you do switch to tires designed for special
terrain use, remember they will be less
acceptable in other circumstances.  For example,
an aggressive mud tire will give excellent grip on
wet, loamy terrain, but less impressive grip on a
hard surface.If you choose a tire with a sticky compound for
added traction, remember that it may transfer
additional loads to the transmission because it
grips so well, especially when riding in situations
that normally place unusual demands on the
transmission.
Complete consumer information can be obtained
from the various tire manufacturer
representatives and dealers.
Some general recommendations for specific
terrain follow:
Hard, Slick Soil
Use tires with many relatively short knobs that
are close together in order to obtain the largest
possible contact patch on the surface.  The rubber
compound needs to be softer for hard ground in
order to hook up, but not so soft that the knobs
roll over easily and affect holding a straight line.
These tires tend to wear more quickly than
standard tires because of the combination of soft
rubber and hard terrain.
Muddy Soil
Use a more open tread pattern to avoid clogging.  
For these conditions, the relatively long knobs
will probably be made from a harder rubber
compound to reduce any tendency to bend back
under acceleration or wear quickly.
Loose, Sandy Soil
Use a tire that is similar in construction to those
needed for tacky soil and mud, but with a few
more knobs. 
						

							Personal Fit Adjustments
130Adjustments for Competition
The following suggestions may make your ride
both more comfortable and more responsive to
your control input.
Control Positioning
• Position the control levers so that you can use
them comfortably when seated and standing.
• Adjust the mounting bolt torque of the clutch
and brake lever assemblies so that they can
rotate on the handlebar in a fall.  If an
assembly does not rotate, it may bend or
break a control lever.  Make sure that the
bolts are torqued securely enough to prevent
slippage during normal operation.
Apply Honda Thread Lock or an equivalent to
the threads of these bolts prior to adjustment to
help ensure the correct torque is retained.
Tighten the top bolts first.
1) control lever mounting bolts
As an alternative, consider wrapping the
handlebar area under the control assemblies with
teflon tape.  Then tighten the assemblies to their
normal torque.  Upon impact, the fully-tightened
assemblies should rotate on the Teflon tape.• Position the shift lever and brake pedal so
they are close to your boot for rapid access,
but not so close that either is depressed when
sitting or standing comfortably on your CRF.
Handlebar Position, Width & Shape
• Position the handlebar so that both gripping
the bar and operating the controls is
comfortable while both seated and standing,
while riding straight ahead and turning.
Tighten the forward bolts first.
• The handlebar position may be moved
rearward either 3 mm (using optional
handlebar lower holders) or 6 mm (by rotating
the standard holders 180 degrees). Refer to
the Service Manual for installation
instructions. Be sure to check control cable
and wiring harness routing after the
adjustment.• Chamfer the edges to remove burrs and other
irregularities or roughness after sawing the
handlebar.
• An alternate handlebar shape, through varying
rise or rearward sweep dimensions, will
provide further adjustment to riding position
and may better suit your particular body size
or riding style. Each of the ergonomic
dimensions of the machine were determined
to suit the greatest possible number of riders
based on an average size rider.
(1)(1)
• Handlebar width can be trimmed with a
hacksaw to better suit your particular shoulder
width and riding preference. Think this
through carefully and cut off just a small
amount at a time from both sides equally. It is
obviously much easier to make the handlebar
narrower than it is to add material. 
						

							Tips
Tips131 Here’s helpful advice on how to transport and
store your Honda, as well as two troubleshooting
flow charts.
Transporting Your Motorcycle .........................132
Storing Your Honda..........................................133
You & the Environment ...................................134
Troubleshooting................................................135 
						

							Transporting Your Motorcycle
132Tips
If you use a truck or motorcycle trailer to
transport your Honda, we recommend that you
follow these guidelines:
• Use a loading ramp.
• Make sure the fuel valve is off.
• Secure the motorcycle in an upright position,
using motorcycle tie-down straps.  Avoid
using rope, which can loosen and allow the
motorcycle to fall over.To secure your CRF, brace the front wheel
against the front of the truck bed or trailer rail.
Attach the lower ends of two straps to the tie-down
hooks on your vehicle.  Attach the upper ends of
the straps to the handlebar (one on the right side,
the other on the left), close to the fork.
Check that the tie-down straps do not contact any
control cables or electrical wiring.
Tighten both straps until the front suspension is
compressed about half-way.  Too much pressure
is unnecessary and could damage the fork seals.
Use another tie-down strap to keep the rear of the
motorcycle from moving.
We recommend that you do not transport your
CRF on its side.  This can damage the
motorcycle, and leaking gasoline could be a
hazard. 
						

							Storing Your Honda
Tips133 If you won’t be riding for an extended period,
such as during the winter, thoroughly inspect
your Honda and correct any problem before
storing it.  That way, needed repairs won’t be
forgotten and it will be easier to get your CRF
running again.
To reduce or prevent deterioration that can occur
during storage, also follow the following
procedures.
Preparation for Storage
1. Completely clean all parts of your CRF.  If
your CRF has been exposed to sea air or salt
water, wash it down with fresh water and
wipe dry.
2. Change the engine oil and filter (page 37).
3. Replace the transmission oil (page 40).
4. Drain the fuel tank and carburetor into an
approved gasoline container.
Turn the fuel valve OFF and remove the
carburetor drain bolt. Drain gasoline into an
approved container.  Reinstall the drain bolt.
WARNING
Gasoline is highly flammable and
explosive.  You can be burned or
seriously injured when handling fuel.
• Stop the engine and keep heat, sparks
and flame away.
• Handle fuel only outdoors.
• Wipe up spills immediately.
5. Remove the radiator cap and coolant drain bolt
(1) at the water pump (2) to drain coolant.
After the coolant has been completely
drained, ensure that the drain bolt sealing
washer is in good condition and reinstall the
drain bolt and radiator cap.
(1) drain bolt (2) water pump
6. Lubricate the drive chain.
7. Remove the spark plug and pour a tablespoon
(0.51 - 0.68 US oz; 15 - 20 cm
3) of clean
engine oil into the cylinder.  With the spark
plug grounded or the engine stop button
pressed in, crank the engine several times to
distribute the oil, then reinstall the spark plug.
8. Inflate the tires to their recommended
pressures.
9. Place your CRF on the optional work-stand or
equivalent to raise both tires off the ground.
Removal from Storage
1. Uncover and clean your CRF.
Change the engine and transmission oil if
more than 4 months have passed since the
start of storage.
2. Uncover the end of the muffler and remove
the rag from the muffler outlet.
3. Fill the fuel tank with recommended fuel 
(page 34).
4. Pour a fresh recommended coolant mixture
(page 41) slowly into the radiator filler hole
up to the filler neck.
Capacity:
1.06 US qt (1.00R) 
at disassembly
0.98 US qt (0.93R)
at draining
Lean your CRF slightly right and left several
times to bleed trapped air in the cooling
system.
If the coolant level lowers, add coolant and
repeat the above procedure.
Install the radiator cap securely.
5. Perform all maintenance checks (page 21).
(2)
(1)
10. Stuff a rag into the muffler outlet.  Then tie a
plastic bag over the end of the muffler to
prevent moisture from entering.
11. Store your CRF in an unheated area, free of
dampness, away from sunlight, with a
minimum of daily temperature variation.
12. Cover your CRF with a porous material.
Avoid using plastic or similar non-breathing,
coated materials that restrict air flow and
allow heat and moisture to accumulate. 
						

							You & the Environment
134Tips
Owning and riding a motorcycle can be
enjoyable, but you must do your part to protect
nature. When you show respect for the land,
wildlife, and other people, you also help preserve
the sport of off-road riding.
Following are tips on how you can be an
environmentally-responsible motorcycle owner.
•Choose Sensible Cleaners.Use a
biodegradable detergent when you wash your
CRF. Avoid aerosol spray cleaners that
contain chloroflur carbons (CFCs) which
damage the atmosphere’s protective ozone
layer. Don’t throw cleaning solvents away;
see the following guidelines for proper
disposal.
•Recycle Wastes.It’s illegal and thoughtless to
put used engine oil in the trash, down a drain,
or on the ground. Used oil, gasoline, and
cleaning solvents contain poisons that can hurt
refuse workers and contaminate our drinking
water, lakes, rivers, and oceans.
Before changing your oil, make sure you have
the proper containers. Put oil and other toxic
wastes in separate sealed containers and take
them to a recycling center. Call your local or
state office of public works or environmental
services to find a recycling center in your area
and get instructions on how to dispose of
nonrecyclable wastes.Improper disposal of drained fluids is harmful to
the environment.NOTICE 
						

							Troubleshooting
Tips135 The items that are serviceable using this Manual
are followed by the page number reference in
parenthesis. The items that require use of the
Honda Service Manual are followed by an
asterisk. 
POOR PERFORMANCE AT LOW AND UNSTABLE
IDLE SPEED
CHECK POSSIBLE CAUSES
1. Check if air
   cleaner is over-
   oiled (P-43)
CORRECT
INCORRECT
INCORRECT
LEAKING
CLOGGED
LOW
WAKE OR
INTERMITTENT
SPARK
CORRECT
CORRECT
NOT LEAKING
NOT CLOGGED
GOOD SPARK 2. Check if the intake
   tube is leaking
3. Check carbureator
   pilot screw
   adjustment (P-124)
4. Check carburetor
   jets and accelerator
   pump for clogs
5. Try spark test
6. Check for
   low compression.
• Over-oiled air cleaner.
•Loose insulator clamp
•Damaged insulator
•Fuel-air mixture too 
lean (Turn the pilot 
screw out) (P-124)
•Fuel-air mixture too rich 
(Turn the pilot screw in) 
(P-124)
•Contaminants in the 
fuel
•Not cleaned frequently 
enough (P-117)
•Faulty, carbon or wet 
fouled spark pulg (P-54)
•Faulty ignition control 
module*
•Faulty alternator*
•Faulty ignition coil*
•Broken or shorted 
spark plug wire.
•Faulty ignition pulse 
generator*.
•Ring worn
•Cylinder worn or 
damaged
•Piston worn or 
damaged
•Head gasket not 
sealing
POOR PERFORMANCE AT HIGH SPEED
CHECK POSSIBLE CAUSES
1. Disconnect fuel
    line at carburetor
    and check for
    clogging (P-34)
UNRESTRICTED
FUEL FLOW
FUEL FLOW
RESTRICTED
CLOGGED
DIRTY
INCORRECT
LOW
WEAK OR
INTERMITTENT
SPARK
NOT CLOGGED
CORRECT
CORRECT
GOOD SPARK 2. Remove air
    cleaner (P-43)
4. Check carbureator
    jets for clogging
5. Check valve
    timing
6. Try spark test
7. Check for
    low compression.
AIR FILTER
NOT DIRTY
3. Install a larger
    carburetor main
    jet (p-124)
CORRECT
CONDITION
WORSE
•  Lack of fuel in tank
   (P-34)
•  Clogged fuel line
   (P-34)
•  Clogged fuel fill
   cap breather tube
   (P-34)
•  Clogged fuel valve
   (P-34)
•  Clogged fuel filter
   (P-35)
 
•  Not cleaned
   frequently enough
   (P-43)  
•  Jet size wrong, rejet
   in the opposite
   direction (P-124)
•  Contaminants in 
   the fuel
•  Cam sprocket not
   installed properly
•  Faulty, carbon or wet 
   fouled spark pulg 
   (P-54)
•  Faulty ignition control 
   module*
•  Faulty alternator*
•  Faulty ignition coil*
•  Broken or shorted 
   spark plug wire.
•  Faulty ignition pulse 
   generator*.
•  Ring worn
•  Cylinder worn or 
   damaged
•  Piston worn or 
   damaged
•  Head gasket not 
   sealing 
						

							136Tips