Needle question when uncorking

I have a 01 xr650r that has been ununcorked all except the needle adjustment. I herd of a couple of people who didnt do this either, the bike runs very strong will I benifit from this? how much, It is at the stock setting, I had nightmares with my Yamahas as far as jetting it runs so good to me that I m not sure if its worth the risk Thanks

I benefited by it but you may not. I don’t know your details But moving it is a minor procedure; remove the side panels, seat, tank (10-15min) I'd try it anyway, you can always put it back and have it just the same as it is now. If anything it’ll give you an idea of what part the needle position plays in the Carb function! I have some links somewhere that explains more. I'll see if I can find them.

But overall don't worry about "nightmares" b/c its a safe experiment, its easy, and I'm sure you are capable!

Have fun!


PS. Some even switch to another needle taper B53E!

Just another thought, I noticed that you are in CO which is higher Alt than I am (200-300), Needle position/taper effects 1/4-3/4 throttle if I remember correctly so by raising the needle one position (lowering the clip)will make it richer so for you it may not improve your performance unless it feels a little lean in that throttle range. (again I don't know your Alt or Riding Temp). But again you can always see for yourself if you care to just tinker! I forgot I lost all my saved links upon reinstalling XP so I can't find any of my saved carb tuning sites! Sorry!.

Quadsan had a ton of links on the post "Jetting for dummies" HERE I haven't looked at them but he has always been very helpful so I'm sure they are informative as well!

Have fun


I`m using that needle taper J.T. advised. I recomend it! Sharpens up throttle response, builds power lower in the rpm range. I was of like mind with you , did not want to mess with it, and I did not know about a performance needle when I uncorked my bike in 2000. Called Baja Designs about a year later to order a jet kit for a friends 650. They told me about the needle, I installed it my friends 650 and the advantages were immediately apparent. You will like the results. :)

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