Honda Crf 250 M Manual

Rear Suspension Adjustments
Adjustments for Competition107 Pin spanners should be used for turning the lock
nut and adjusting nut.  See page 147 for optional
pin spanners.
Spring pre-load length (Standard spring)
Standard:10.29 in (261.3 mm)
Min. :9.88 in (251 mm)
Spring pre-load length (Optional spring)
Min. (Softer, 5.1 kgf/mm): 9.92 in (252 mm)
Min. (Stiffer, 5.5 kgf/mm): 9.80 in (249 mm)
Min. (Stiffer, 5.7 kgf/mm): 9.88 in (251 mm)
The rear suspension can be adjusted for the
rider’s weight and riding...

Rear Suspension Adjustments
108Adjustments for Competition(3) rebound damping adjuster
To adjust to the standard position:
1. Turn the adjuster clockwise until it will no
longer turn (lightly seat). This is the full hard
position.
2. Turn the adjuster counterclockwise 9 clicks
with the punch marks on the adjuster and the
shock absorber aligned.
Rear Suspension Damping
Compression Damping
Compression damping may be adjusted in two
stages with separate adjusters.
The high speed damping adjuster (1) is...

Rear Suspension Adjustments
Adjustments for Competition109 4. Calculate the race sagdimension.
To do this, subtract the loaded with rider
dimension (step 3) from the unloaded
dimension (step 2).
Standard Race Sag: 3.9 in (100 mm)
Adjust spring pre-load as necessary to obtain
the desired handling results.
Decreasing the race sag dimension (example:
3.5 in, 90 mm) improves turning ability for
tight terrain at the cost of slightly reduced
straight line stability.
Increasing the race sag dimension (example:...

Rear Suspension Adjustments
110Adjustments for Competition
Because of the great absorption quality of the
shock bumper rubber, it may be difficult for you
to notice when your CRF’s suspension is
bottoming.  Some riders may think the damping
or perhaps the leverage ratio is too harsh.  In
reality, the problem is most likely insufficient
spring pre-load or a spring that is too soft.  Either
situation prevents utilizing the full travel.
Keep in mind that a properly adjusted suspension
system may bottom...

Suspension Adjustments for Track Conditions
Adjustments for Competition111 Soft Surface
On soft ground, sand, and especially mud,
consider increasing compression damping front
and rear.
Sand often requires a bit more rebound damping
to minimize rear end kick.  Although sand bumps
are usually larger, there’s more distance between
them, giving the shock more time to recover.
You may want a little bit stiffer front suspension
for sand tracks to help keep the front end up and
improve straight-line...

Suspension Adjustment  Guidelines
112Adjustments for Competition
Follow the procedures described below to accurately adjust your CRF, using the methods described on pages 94 - 108.  Remember to make all adjustments in
one-click increments.  Test ride after each adjustment.
Front Suspension Adjustment
Adjustments for Type of Track
Adjustments for Too Soft/Stiff Damping
Hard-surfaced track
Sand track
Mud track
Begin with the standard setting.  If the suspension is too stiff/soft, adjust according to the...

Suspension Adjustment  Guidelines
Adjustments for Competition113
Stiff
suspension
Symptom
Initial travel too stiff:
•
Stiff on small bumps while riding at full throttle in a straight line.•Stiff on small cornering bumps.
•Front end wanders while riding at full throttle in a straight line.
Middle travel too stiff:
•Stiff on bumps when cornering.
•Front end wanders when cornering.
•Stiff suspension on bumps, especially downhill bumps.
•While braking, front end dives during initial travel, then feels...

Suspension Adjustment  Guidelines
114Adjustments for Competition
Rear Suspension Adjustment
Adjustments for Type of Track
Symptoms and Adjustment
•Always begin with the standard settings.
•Turn the low speed compression and rebound adjusters in one-click increments, and the high speed compression adjuster in 1/6 turn increments at a time.  Adjusting two or
more clicks or turns at a time may cause you to pass over the best adjustment.  Test ride after each adjustment.
•If, after setting, the suspension...

Carburetor Adjustments & Tuning Tips
Adjustments for Competition115 The carburetor on your CRF should perform
suitably with the standard recommended settings
under average load, climatic, and barometric
conditions. However, to fine tune the engine’s
power output, the carburetor may require
adjustments for specific competition needs.
Optional main jets and slow jets are available for
your CRF.  See your Honda dealer.
Any engine or airbox modifications or the use of
an aftermarket exhaust system may...

Carburetor Adjustments & Tuning Tips
116Adjustments for Competition
Accelerator Pump Circuit
The accelerator pump circuit operates when the
throttle is opened. As the throttle valve (1) opens,
the pump rod (2) depress the diaphragm (3). At
this time, the inlet check valve (4) is shut
resulting in a sharp increase in pressure in the
pump chamber (5). The outlet check valve (6)
then opens, supplying fuel to the main bore via
the accelerator nozzle (7).
(1) throttle valve (5) pump chamber
(2) pump rod (6)...