Honda CRF450R Carburetor Clean  

Dirt bikes are supposed to get dirty, hence the name. However, the carburetor on a dirt bike like the Honda CRF 450R doesn't handle the grime well. 

A little bit of dirt can foul up your dirt bike's carb and kill its performance. Knowing how to clean the carburetor on a Honda CRF450R is a simple "do it yourself" task that's essential to your motorcycle's maintenance. Here's how to clean the carburetor on a Honda CRF450R. 

Tools and Parts Needed - Honda CRF 450 Carburetor Cleaning

NOTE: The parts you'll need will depend on the condition of your carburetor. If your carb has been well maintained over the years, you may only need a can of carb cleaner and a couple of individual parts. However, if your carb has been neglected, you may need a complete carburetor parts kit.

Tools 

  • 3/8th ratchet and extensions
  • 8mm, 10mm, 12mm sockets
  • 3mm, 4mm Allens
  • 10mm, 12mm wrenches
  • Screwdrivers
  • Pliers

Step 1. Remove the seat, side covers and engine shroud.

Honda CRF carb cleaning

PRO TIP: With the seat and shroud removed, now is an ideal time to replace the spark plug.

Step 2. Remove the six bolts securing the rear subframe. Next, loosen the clip on the air intake and remove the rear subframe, complete with the air filter housing.

Honda CRF450R subframe

Honda CRF450 air filter housing

Step 3. Pull the carburetor out from the frame and remove the throttle cover, throttle cables and fuel pipes. 

NOTE: Memorize how the two throttle cables connect to the carb so you can reinstall them in the correct order.

Honda CRF dirt bike carburetor cleaning

Step 4. Clean the carb with contact/brake cleaner to prevent dirt from the exterior of the carb from entering the interior.

Honda CRF 450 carb cleaning

Step 5. Remove the float chamber, followed by the jets and the float itself.

Honda CRF450 carburetor float chamber

Honda CRF450 motorcycle carb needle jets

Step 6. Clean the jets with carburetor cleaner

NOTE: If carb cleaner doesn't clear a blockage in a jet, don't use a wire to clean it out because the wire will damage the internal bore of the jet. If a jet can't be cleaned, replace it with a new one.

Honda CRF motorcycle carburetor cleaning jets

Step 7. Remove the air/fuel mixture screw and the spring, washer and O-ring. Clean the screw, spring and washer with carb cleaner. 

NOTE: Do not use carb cleaner on the O-ring, as it will damage it.

Honda dirt bike carburetor cleaning

Step 8. Remove the carburetor's top cover, followed by the throttle valve and jet needle assembly. Inspect the needle for any signs of wear, and replace it if necessary. Clean the assembly with carb cleaner.

NOTE: Do not use carb cleaner on the O-ring of the valve's baffle plate, as it will damage the O-ring.

Honda CRF 450 carburetor top cover

Honda CRF motorcycle carb cleaning

Step 9. Blow compressed air through all the channels of the carburetor body to clean out any dirt. Also, blow air through the jets and screws you've removed from the carb. 

NOTE: Even a little dirt can block a carb jet, so everything needs to be completely clean and free of contaminants before the carb is reassembled.

Carb ckeaning Honda CRF450 dirt bike

Step 10. Remove the accelerator pump cover from the float chamber and inspect the diaphragm for wear or cuts. Replace the diaphragm if necessary.

Honda CRF450 dirt bike carb accelerator pump

Step 11. Reassemble the carburetor in the reverse order you disassembled it. Remember, everything needs to be spotlessly clean so there is no trace of dirt or debris within the carb once it's reassembled.

Honda motorcycle carburetor rebuild

Step 12. Reinstall the carburetor, the subframe and air filter housing, the engine shroud, side covers and seat.

Honda CRF450R dirt bike carb cleaning

Honda CRF450 dirt bike carb clean

Want to see how to clean the carburetor on a dirt bike other than a Honda CRF450? Watch the video below to see how to clean the carburetor on a Kawasaki KLX 110 dirt bike.

 

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