Uncorking the Honda XR650R BRP by Bob Naumann on 4Strokes.com

4Strokes.com Honda Technical: Uncorking the XR650R BRP By Bob Naumann

Here is how Bob Naumann uncorked his 2000 Honda XR650R Big Red Pig (BRP). You may find it helpful to also follow along in a service manual when doing these mods, or any mods for that matter. For a complete list of factory parts and descriptions, please go here: Uncorking the Honda XR650R (Honda Tech Bulletin)

Warning: The screws that hold the carburetor together are very soft and can be ruined easily if you are not careful. Use a good quality #2 Philips screwdriver, apply firm pressure, and take your time removing the screws.

Tip: Some folks have replaced the Philips head screws on carburetors with Allen head screws to make them easier to remove in the future. You can try doing a search in the forums for topics on this subject.

1. Work in a well ventilated area. If you have a lift, put your bike on it. To minimize the amount of gas that is likely to spill, turn off the fuel petcock valve and run the engine until it runs out of gas.	2. Remove the seat. There are two bolts, one on either side that have to be removed. Note the bolts are different. The longer one goes in the right side of the seat. Lift the seat up and out towards the rear of the bike.	3. Now remove the gas tank. Remove the radiator guards on the front sides of the gas tank by removing the two Philips screws and one bolt on each side.	4. Remove the Philips screw on top of the tank that holds a metal loop and rubber strap. Put the screw back in so you remember how it and the spacer are positioned.	XR650R Uncork Tech Article Sponsor

5. There are two bolts under the tank that were hidden by the radiator guards. Remove these two bolts.	6. Loosen the hose clamp on the carb end of the hose from the petcock to the carb. Carefully lift the tank up and watch that the hose slides off of the carb.	7. There are several vent/drain hoses attached to the carb. They all go towards the rear shock area. There's a large plastic twist clamp holding them to other hoses & cable.	8. Place the end of the small drain hose that comes from the bottom of the carb into a gas can on the left side of the bike.

9. Open the drain valve on the bottom right side of the carb using a standard screwdriver. Close the drain valve by re-tightening the screw.	10. Remove the carb from the bike by loosening the 3 clamps on the carb air inlet and outlets with a Philips screwdriver.	11. Move the choke lever to the fully closed position. This will position the choke plate inside the carb body. From the right side, pull back the rubber flange while applying pressure to the carb from the left side.	12. When the carb does come out, the front piece (insulator) will start to come off the cylinder. Pull the insulator off the carb once it's loose.

13. Carefully maneuver the carb back through the frame to bring it out on the other side. Now you can remove the throttle cables. Take note of which one is longer, and remember that it goes on the bottom.	14. Remove the top of the carb and replace the needle from the kit, P/N: 16012-MBN-641. Clean the slide with carb cleaner and reassemble the top cover.	15. Flip the carb over and remove the float bowl. Replace the needle seat from kit, P/N: 16012-MBN-641 (B53E). Also install the main jet, P/N: 99101-357-1750 (#175), and pilot jet, P/N: 99105-MBN-0680 (68s). Reinstall the float bowl.	16. Note the positions of the two insulator clamps and remove them from the old insulator. Reinstall them on the new insulator the same way.

17. Install new carb insulator using P/N: 16211-MBN-640 (Honda Power-Up Kit, circle shaped instead of double-D) on the front of the carb, being sure to align the notch.	18. Reattach the throttle cables and check operation. Push the carb back through the frame on the right side. Position the insulator on the cylinder. Pull the airbox out working the back end of the carb inwards. Make sure the choke is fully closed.	19. Push the carb towards the cylinder to make sure that the insulator is fully seated on the cylinder. Tighten the insulator clamp on the cylinder end. Then push the airbox intake piece so it's fully seated on the carb and tighten that clamp.	20. Remove both the rubber and plastic baffle pieces from the back of the airbox (per Honda Tech Bulletin).

21. Replace the muffler insert using P/N: 18317-MBN-640. You can drill out the insert instead of using the HRC part. I wanted to be able to reverse the mod so I used the HRC part.

Okay, now you are done uncorking your Big Red Pig! Roll it outside, turn on the fuel petcock valve, pull in the compression release, and kick it over a few times. Then do your normal starting routine. You should notice it starts up more easily than before. Now take it out for a test ride. Be careful, as it may wheelie instantly when you crack the throttle open, now that the power is at full potential. Bob says the above mods made a dramatic difference on his 2000 Honda XR650R BRP!

Credits: Article written by Bob Naumann of Plano Texas and edited by 4Strokes.com. (Bob thanks Brian, Eric, Neil, Gene, Dayle, Kevin, Peter, and et al for their help with his BRP uncorking mods.)

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