YZ 250 F 08 problems

First of all let me give the data of my YZ 250 F 08 model:

Model (YZ or WR 250F):YZ250F 08

Timing (WR-YZ):YZ

Main jet:170

Pilot Jet: 48

Fuel screw (turns out): 2

Needle model/Clip position: GYTR/4th

Airbox lid (on or off):It´s an Yz

Pipe: Complete Leovince X3 Ti

Altitude where you ride:Sea level to 2, 3 km´s above see level of a bit more somethimes.

Temperature where you ride:0 in the winter to 35celsius in the summer

Have my bike for a year now and never had a single problem except when it camed but i put a smaller MJ and it was perfect since now.

The problem started when i cleaned the carburator.

After cleaning it i drove all day and all was ok but at the end of the day it was booging in low rpm´s so i check all the pieces in the carburator and jets and put a new GYTR needle.

Everything is perfect with the bike, valves, piston, cylinder, all checked and some parts exchanged during the time i have it.

So i put a GYTR needle with a Main jet of 176.

At this moment i put a 170 Main Jet and it seems to be better.

Yesterday i rode all day in a motocross track and the bike is fine but after riding for some time i went to some hills and i noticed that with inclination is when the bike fails.

With no inclination all ok, with inclination not ok, when i have the thotlle in 1/4 or a bit more it chockes and real power only in high revs.

Today i missed a XC event after doing pratices because it had too much hills and the bike was not ok...i am pissed as you guys can understand.

Tomorow i will try a 168 MJ with the 2nd clip position but i am starting to think that i have a problem in the carburator but i don´t know how to say it in english "the ball"????

Tomorow i will meet my mechanic and make some tests on a nice hillclimb i kepp you posted.

Opinions are obviasly welcome.

Check your float height.


That was the name is was looking for.

Will check it

Float heigth at normal measure.

I made a mistake in the first post, the clip was at the 5th position, now it´s on the 3th and i decreased the MJ for a 168.

I could not drive it much time today but it seems that it is ok.

This thursday i have a schedule train session and i will see if the problem is fixed now.

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