CRF300L CAMSHAFT SWAP for CBR300R Cams and Valve Adjustment

Introduction

In this tutorial, we will guide you through the process of swapping camshafts in a CRF300L motorcycle using CBR300R cams, along with the necessary valve adjustments. This modification aims to enhance the bike's performance by improving airflow and increasing horsepower. We'll cover the tools you'll need, step-by-step instructions for the cam swap, and tips for ensuring everything is adjusted correctly for optimal performance.

Chapter 1: Understanding Camshafts

• What are Camshafts?

  • Camshafts control the opening and closing of the engine's valves, allowing air and fuel to enter the combustion chamber and exhaust gases to exit.
  • Each engine has two intake and two exhaust valves.
  • Cams rotate at half the engine speed and are responsible for valve lift and duration.

• Impact on Performance

  • A more aggressive cam can increase horsepower but may reduce reliability and low-end power.
  • It's essential to balance performance gains with engine reliability.

Chapter 2: Selecting the Right Cams

• Choosing CBR300R Cams
  • The CBR300R and CRF300L share similar engine specifications, making the CBR cams a suitable upgrade.
  • While swapping, ensure the parts fit without requiring additional modifications.
  • The CBR300R cams typically provide better mid-range and top-end power with only a slight drop in low-end performance.

Chapter 3: Tools Needed for the Swap

• Basic tools required:
  • 5/8” spark plug socket
  • 10mm and 17mm socket wrenches
  • Breaker bar
  • Magnet tool
  • Feeler gauges
  • Safety wire
  • Oil for lubrication
  • Torque wrench

Chapter 4: Removing the Old Cams

1. Prepare the Engine

   • Ensure the area is clean to avoid debris entering the engine.
   • Remove the spark plug cap and the spark plug using a magnet tool for easy retrieval.

2. Access the Valve Cover

   • Remove the two 10mm bolts securing the valve cover.
   • If obstructed by components like the radiator, detach them carefully.

3. Remove the Cam Chain Tensioner

   • Locate and remove the cam chain tensioner to relieve tension on the cam chain.
   • Ensure you note the position of the chain.

4. Set Engine to Top Dead Center

   • Use the breaker bar to turn the engine until the timing mark aligns with the top dead center (TDC) indicator.

5. Take Out the Camshafts

   • Loosen the bolts securing the camshafts in stages to prevent damage.
   • Remove cams and keep them organized for comparison.

Chapter 5: Installing New Cams

1. Prepare the New Cams

   • Compare the new CBR300R cams with the stock ones, noting any differences in lift and duration.
   • Apply a touch of oil to the new cams for lubrication during installation.

2. Install the New Cams

   • Position the new cams correctly, ensuring the timing marks are aligned.
   • Tighten bolts gradually to the specified torque.

3. Reinstall the Cam Chain Tensioner

   • Follow the correct procedure to ensure no excessive tension on the chain.

Chapter 6: Valve Adjustment

1. Check Valve Clearance

   • Rotate the engine a few times to settle components.
   • Use feeler gauges to measure the gap between the cam and the valve when closed.
   • The gaps should meet factory specifications.

2. Adjust Shims as Necessary

   • If gaps are too tight or loose, replace shims accordingly.
   • Record the thickness of the shims removed to ensure accurate replacements.

3. Recheck Clearance

   • Once adjustments are made, check clearances again to confirm they are within specifications.

Chapter 7: Reassembly

• Final Steps
  • Clean and reinstall the valve cover and secure with bolts.
  • Reconnect any components that were removed for access, such as the radiator.
  • Ensure all hoses and electrical connections are secure.

Conclusion

You have successfully swapped the camshafts on your CRF300L with CBR300R cams and adjusted the valves for optimal performance. This modification should provide a noticeable boost in power and efficiency. For next steps, consider tuning your bike’s exhaust system for even better performance enhancements and check out additional videos for further modifications. Enjoy your ride!