Honda CRF250X, Owner'S Manual & Competition Handbook

Page: 138 / 180

Carburetor Adjustments & Tuning Tips
Pre-Adjustment Checks
Before adjusting carburetor settings, check the
following:
• air cleaner
• air leaks
• float level
• clogged carburetor jets
• spark plug fouling (improper heat range or
other cause)
• freshness of fuel
• owner modifications (such as exhaust system,
holes in the air box, etc.)
• ignition timing
• compression
If the above check out, then, adjust the carburetor
for your specific racing conditions. Engine
response and appearance of the firing end of a
spark plug are highly indicative of the engine
condition.
132
Adjustments for Competition
Adjustment Procedure
1. Turn the pilot screw in until it is lightly seated
and record the number of turns. Turn the pilot
screw (1) out the same number of turns.
(1) pilot screw
2. If the engine is cold, start it and warm it up
three minutes. Then shut it off.
3. Connect a tachometer to the engine.
4. Shift into neutral. Start the engine.
5. Keep the motorcycle in an upright position.
6. Adjust idle speed with the throttle stop screw
(2).
Idle speed:
1,700 ± 100 rpm
(2) throttle stop screw
(1)
(2)