| 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. |
|
 |
| 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
pieces (baffles) from the back of the airbox. |
|
 |
| 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.) |
| 4Strokes.com Technical: Honda Related |
