Removing the EPA parts from the stock XR650R

Note: This works on any XR650R, model year 2000-2004



Take the rubber boot off the airbox. Take out the plastic insert just forward of the rubber boot.



Replace the stock manifold with part number 16211-MBN-640. Here is a picture of the manifold you want to replace.

3.    Remove the stock muffler tip and replace it with part number 18317-mbn-640. 

Or buy a 2" hole saw and drill out the end of the tip. Strap your bike in the back of your truck or on your trailer with tiedowns to prevent it from tipping over while you drill.  Use some light grade oil and oil it every few seconds while drilling.  The good part about drilling it out is that it is much cheaper then the alternate tip from Honda and it does NOT defeat the spark arrester.  I have received a lot of emails asking if this makes the muffler louder.  It is not as loud as a stock XR600R pipe with the baffle removed.  
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This is a picture of the hole saw by itself. (without the drill attached) This is a picture of the 2" hole saw sitting in the end of the tip. (without the drill attached)

This is a picture of the actual end piece that is drilled out.   (the piece that you want to remove to make the tip less restrictive) Here is a picture of the epa muffler tip drilled out.

4.    Change the main jet from a 125 to a 170, 172 or 175 depending on altitude. 

5.    Move the needle clip from the 2nd position to the 4th position in the carb.


6.    Change the stock pilot jet from a 65s to a 68s (or bigger depending on altitude), The part number for the 68s is: 99105-MBN-0680.  The XR650R seems to be overheating at low speeds because the bottom end is too lean. This also helps starting the XR650R.

Optional:  You can change the stock radiator cap from a 1.1 bar to a 1.6 or 1.8.  When the coolant heats up and expands, it needs somewhere to go.  The radiator cap relieves that pressure by allowing coolant to the overflow tank when the cap pressure is reached.  Some riders have switched to a Kawasaki KX 500 cap, Kawasaki part#: 49085-1059 for a '92-'96 KX500. It's a 1.8 bar cap.   Be forewarned, this mod puts increased stress on the cooling system and can cause hoses etc. to fail sooner than they would with the stock 1.1 bar cap.

Now the XR650R will rip!

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