How to Install ATV Racing Parts

Make your ATV more competitive by installing racing parts and components.

Once you begin exploring the numerous racing components that are compatible with an ATV, you realize the only limits might be your budget. Aside from building a full-blown racing engine and installing trick suspension, typical racing parts include a racing carburetor, high-volume fuel pump and a racing clutch. Tuned exhausts are a must for any level of competitive riding. Apply your mechanical expertise and the information in your service manual to install ATV racing parts.

Things You'll Need

• Your ATV service manual
• Metric tools
• Torque wrench
• Racing carburetor or racing carburetor kit
• Air filter cartridge
• High-volume fuel pump
• Racing clutch or clutch kit
• Tuned exhaust system

Instructions

Carburetor and Fuel Pump

1. Review the fuel system specifications for the particular ATV class you plan to enter. Select a Mikuni or Keihin racing carburetor that is the maximum size for your class. For example, your 2009 Honda TRX400X has a 38 mm carburetor that you might replace with a 42 mm unit. Upgrade the stock carburetor by installing larger jets from a kit when specifications prohibit bigger carburetors.

2. Remove the rider's seat and both upper engine guards on each side of the ATV. Turn the fuel petcock off and disconnect the fuel line from the carburetor. Disconnect the throttle cable and the air filter from the carburetor.

3. Loosen and remove the intake manifold nuts on the carburetor intake flange. Save the nuts. Pull the carburetor and the rubber ring gasket off the intake manifold.

4. Install the bigger carburetor on the ATV and include a new ring gasket. To upgrade your stock carburetor, disassemble the unit on your workbench and install the larger jets, larger valve needle and new gaskets from a racing kit. Include a new air filter cartridge with either modification. Make sure the fuel line clamp and manifold nuts are tight when you install the carburetor. Reconnect the throttle cable to the carburetor.

5. Refer to your service manual and locate the electrical connection for your stock fuel pump. Disconnect the power source wire for the pump at the connector shown in the manual. Loosen the fuel line clamp and pull the line off the pump. Remove the stock fuel pump from the ATV.

6. Install the high-volume fuel pump in the factory location. Connect the power source wire from the new pump to the factory electrical connector. Reattach the fuel line to the pump and tighten the clamp securely.

Racing Clutch or Kit

1. Read the instructions that came with the racing clutch or racing clutch kit from start to finish before starting the work. Look at the section in your service manual that describes clutch replacement and remove any external components, such as the floorboard or shift lever, as necessary to access the clutch cover.

2. Remove and save the clutch cover bolts. Pull the cover off the clutch case and save the cover. Depending on the manufacturer of your ATV, you will be instructed to remove a clutch belt and belt pulley, or a pressure plate to access the clutch components. Follow the instructions and save any factory parts not included with the racing clutch or clutch kit.

3. Remove the clutch springs, clutch plates and metal clutch spacers from the clutch case by hand. You remove the stock clutch basket when installing a racing clutch. The stock basket remains when installing racing springs, clutch discs and metal spacers from a clutch kit. Install the clutch components as described in your manual.

4. Torque the pressure plate bolts to the specified torque in your service manual. Typical procedures have you torque the bolts in a crisscross pattern. Reattach the clutch cover using the saved bolts that you torque as specified in your manual. Make sure to adjust the clutch cable as described in your manual before riding the ATV.

Tuned Exhaust

1. Talk to a racing accessory specialist or racing mechanic and determine the type of exhaust pipes, baffles and spark arrestor combination that boosts engine performance at low to mid-range speeds. Include new exhaust manifold gaskets with the tuned exhaust. Make sure to get new exhaust brackets, if necessary.

2. Park your ATV and allow the engine and exhaust pipes to cool completely. Look at the section in your manual that describes removing the exhaust system. Take note of any fairings or cables that are part of the process and remove or disconnect these.

3. Remove and save the exhaust manifold bolts at the header flanges. Ease the headers away from the exhaust manifold by hand and discard the factory exhaust gaskets. Remove the exhaust pipe brackets and remove the factory exhaust system. Save the brackets if new brackets are not needed or included with the exhaust.

4. Take the factory exhaust apart and slide the header flanges off the factory pipes. Slide the flanges onto the new pipes and assemble the tuned exhaust.

5. Put the new exhaust gaskets on the engine manifold. Position the exhaust at the side of the ATV and secure it with the saved or new brackets. Slide the header flanges against the exhaust manifold and secure them using the saved bolts. Start the ATV and listen for exhaust leaks. Turn the engine off and tighten any bolts as needed.

Tips & Warnings

• Always inspect factory parts, such as the fuel lines, clamps and throttle cable, before reconnecting them. Replace any parts that are worn or suspect in any way.

• Do a complete tune-up after installing carburetors and exhaust systems.

• Talk to fellow racers and racing mechanics for suggestions on ignition modules and ignition timing settings for racing.

• Test drive the ATV at moderate speeds before racing the motorcycle.

References

• Total Motorcycle: 2009 Honda TRX400X Specifications
• Dalton Industries: Dalton Pro ATV Clutch Kit
• all-motorcycle-accessories.com: Motorcycle Exhaust System Information