XR650R exaust pipe
 

Hi
I have been told that to drammaticaly improve the performance of this engine at low rpm one needs to change the exaust pipe with a specific after market replacement.
Is this true? If so which one is the best brand?

Many thanks in advance

the guy at PDQ (who tunes bikes for a living) used the stock can on his own bike so, for the European bike, I reckon its more about having the right silencer tip rather than changing the whole can. I'd expect Ozzie ones to be heavily restricted cos they supposedly only kick out 20hp compared with 45 over here.

Also think about opening up your airbox, but bear in mind that your carbs will need rejetting if you do either (or both) will probably only give you around 5 extra horses at best.

try www.4strokes.com

Depends on what model and restriction your bike has in place.

If its "uncorked", as in the restrictor in the airbox isnt present (brass coin thingy) then changing the tip to a racing tip helps allot.

Stock "uncorked" bikes run jets 65 pilot and 175 main. Check these !!!

If you take the baffle/tip out of the exhaust then up the pilot jet to a 68, it will start, run and blast like a dream.

for road use, many peopel drill holes into the airbox cover and cover with a fine mesh as it helps the engine breath quite a bit.