Whats up with jetting charts?

2 replies to this topic
  • maddmickey

Posted August 17, 2005 - 08:07 PM


I have a 2001 xr650r uncorked, side drilled, uni filter, and just put on a white bros pro meg. It seemed sluggish in mid to high revs, so I changed the 175 main to a 180 and moved the needle clip to #4 down. It really woke the bike up, and dosent show signs of being rich. I have a 70s slow jet on order, and am thinking of trying a 182 main just to see. What confuses me is that I am running at 5500 ft, and all the info i see says this is too rich. I know that some of you guys running at sea level are only running 175 mains. Any thoughts? shoud I try a 182 or 185 or is there something im missing?

I would also like to thank all of you experienced guys for helping out us newbies, thanks!!

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  • Ramcc4x4

Posted August 18, 2005 - 10:47 AM


I have run a 70s pilot and 185 main in the High Desert. My bike ran very well like that. I did have the same concerns you have. My buddy I was riding with didn't have the airbox mod or header like I had and he was able to run a 180 at the same elevation.

  • TimBrp

Posted August 18, 2005 - 12:02 PM


With the side drilled and airbox restrictions gone your sucking in alot more air. I'd say a 178-180 should be fine. You could probably stay with the 68s pilot unless your getting some popping on decel or starting issues. Go with the 70s when it gets below 50 degrees out.

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