What a day... Ive just had the best ride ever... I never realised how quick this bike was until I hit the trails. Passing 520EXC's up long rutty hills, Im still grinning This bike absolutely rocks...suspension, motor, power and the traction is fantastic. I dropped it for the first time and tweaked the bars but it was worth it: Time for a stronger pair.

My question is.. What can I do to my stock jetting(AUS model) to make the bike run better at higher altitudes? I was getting a lot of popping and hesitation when I'm hard on the throttle. Will the OBELP (YZ250f) needle help?? As Ive already purchased it. Or do I have to change the jets? Ive done all free mods as well. Im new to jetting so any help will be appreciated.

Cheers,

Dave

Hard on the throttle....does that mean at full throttle? If you're getting missing and popping at full throttle it sounds like you may need a bit smaller of a main jet. However.... I noticed on the bottom of your post it says 01wr250F stock. How "stock" is it? Have you removed restrictive insert from the muffler? Removed air box lid? Ground throttle stop down? Snipped grey wire? If you havn't done these mods first, don't waste your time jetting because it won't run worth a darn anyway.

Thanks 4 the reply KSP,

All the free mods have been done- Airbox Lid, Exhaust Insert, Throttle Stop. I went to a Yamaha dealer today who told me to swap the WR needle with the YZ one. This should clear up the rev range. The bike did not want to rev as hard as usual and occassionly it would make a popping sound and die. Im hoping the OBELP needle will cure this.

Dave

Daveee
I've got the same bike with no real problems running at any altitude (sea level to Mt Hotham).

I'm travelling at the moment so I don't have my carb specs handy although I believe they are:
40 pilot, 168 main, 1.5 turns out on air screw, OBELQ needle (different to ADB suggestions) on clip #2, no air box lid, derestricted stock exhaust. I run a Vortex ignition & an NGK CR8EIK Iridium plug with stock WR timing. Its nice!!
If my specs turn out to be different I'll let you know by the weekend.
Given summers here & its getting hot I may adjust the main from where its at now - thats all.
Hope this helps & let me know how you go.

Same for me as far as 1st trial ride on my new 02 wr250. I live in New England where the riding is rather technical, wet, rocky and slippery. The bike handles quite well. I am coming from 4 years of KTM 200 (exc's and mxc's) and last year was riding a highly modified 01RM250 (enduro mods) and the WR is very quick. I did all the mods (airbox, wire, exhaust cam, vortip exhaust insert) and the bike is totally different from stock. Stock, the bike is a total dog. With the mods, it is plain fast. wir/Cam timing mods make the real difference, good low end traction (you cannot stall this bike) and great power from mid to upper. Now I have to work on suspension which is too stiff for this type of riding. Finally the bike is actually very comfortable. Much less buzzing than all my 2 strokes...good for my 42 year old wrists.

WOW,

That OBELP needle really did the trick
No more hesitation on acceleration and the front wheel wants to lift more than ever. Nev, where in Vic do u usually ride??

Dave