Modifying Honda Motorcycle XR650R For Higher Performance

This carburetor tuning Information is provided exclusively for preparing the motorcycle far closed-course competition only. Damage from competition use is not covered by the Distributor’s Limited Warranty. For all service procedures and carburetor adjustments, refer to the Service Manual, Section 5. All jetting recommendations are based on an unmodified engine. Air temperature, humidity and altitude can also affect fuel mixture and running condition and may require additional adjustments.

To obtain the higher performance in the XR650R you must change the intake manifold, exhaust core/spark arrester, and change the carburetor settings by changing The main jet and jet needle.

Be sure to remove both air intake restrictors. The following table lists the pad numbers and actions required to modify the XR.

2600 XR650R Footpeg Washer

Step 9 of the Set-Up instructions does not specifically mention that the 12.5 mm washer
found in the loose parts bag is to be installed or the right footpeg rear bolt.

Note that the washer is a loose fit on the bolt and is mounted with the sharp side of the washer facing toward the engine. Additionally, if the bike is used in competition, use a light thread lock fluid and, even if safety wired, be sure to check the footpeg bolts regularly.
98-99 TRX450ES

Battery Discharge Campaign Extension

In California. modifying an XR650R registered for off-road use(i.e., green suckered) is considered tampering with an emission system and is prohibited by and punishable according to state regulations.

The TRX450ES Battery Discharge Product Improvement Campaign {1998-99 TRX450ES Battery Discharge Service Bulletin, TRX450ES
#1) was originally supposed to end on March 3t,2000.

The end date has been extended to July 31,2000. The Service Bulletin will be reissued and new customer reminder postcards will be sent.