While it is technically possible to modify a Honda XR 650L to increase its power output, achieving the same or more power than an XR650R may be challenging. The XR650L and XR650R are different models with distinct engine designs and performance characteristics.
The XR650R is a high-performance off-road race bike specifically designed for competition, featuring a liquid-cooled engine with a more aggressive cam profile, larger carburetor, and higher compression ratio compared to the air-cooled XR650L.
That being said, there are several modifications you can consider to improve the power and performance of the XR650L:
Exhaust System: Upgrading to a high-performance exhaust system can improve exhaust flow and increase power output. Aftermarket exhaust systems designed for the XR650L may offer performance gains.
Air Intake: Enhancing the air intake with a high-flow air filter or a performance air intake kit can improve airflow to the engine, potentially increasing power and throttle response.
Carburetor and Jetting: Rejetting the carburetor or upgrading to a larger carburetor can optimize fuel delivery and improve performance. Proper jetting adjustments should be made to match the modifications and local altitude conditions.
Engine Tuning: Engine tuning, such as adjusting the timing, valve clearances, and fuel mixture, can help optimize performance and power output.
Camshaft Upgrade: Installing a performance camshaft can enhance valve timing and lift, leading to improved power delivery. However, camshaft upgrades may require additional modifications, such as valve spring upgrades and careful tuning.
Bore and Stroke Modifications: Increasing the engine displacement through a bore and stroke modification can potentially increase power output. However, this modification requires specialized knowledge, precision machining, and careful balancing of internal components.
It's important to note that modifying a motorcycle's engine can have implications for reliability, emissions compliance, and warranty coverage. It is recommended to consult with experienced mechanics or performance specialists who have knowledge of the XR650L and can provide guidance on suitable modifications based on your specific goals and riding needs.