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CRF250X Question for JD

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I have two CRF250X's the airbox has been fully opened with the backfire screen removed and the baffle and spark arrestor screen removed from the end can. The carb has been left standard with 40PJ and mixture screw 2-1/4 turns out. I initially installed the JD jetting red needle 5th. clip from top at times the motor was a little difficult to start and always needed the choke.When cold it would hesitate at partial throttle but was OK when warmed up however I did notice that when you blip the throttle the revs would hang up like you still had the choke on. Also when the motor got hot the performance seemed to decrease. My thoughts were that it could be a bit lean so I installed the blue needle 3rd clip from the top. The motor now starts instantly and does not always need choke, the revs no longer hang up and when the motor is hot performance is the same as when warm, in short the motor now rips much better than the red needle. What are your thoughts on this? do you think I should I have changed the PJ to a 42 should I do this and go back to the red needle or do you have any other suggestions? My riding is all in the desert (sand) from sea level to 1000 feet max. Temperature is between 90 and 115F with humidity 30 to 70% obviously the higher the temperature the lower the humidity. sigsdxb@eim.ae <font color="black">

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By using the leaner clip position, the jetting is only richer at idle and then leaner above. If the combination is working good, stay with the setting.

James

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<font color="black"> Thanks for your quick reply.If you do not mind could you expand further. Do you think it may be worth trying the blue needle in clip position 4th. from top as per the recommendation included in your jetting kit, this I guess would richen it from idle up to full throttle compared to 3rd clip position. Also as per your recommendation the blue needle is for temp below 50F why does it seem to be better than the red needle for temp range 95 to 115F with the humidity 70 down to 30%? I had assumed the red needle would have been for all temp above 50F. I am just trying to understand the effects of very high (dry) temp as they would seem to have the same effect as temps 50F and below, am I right? I have experienced this on three CRF250X's so I do not feel that it is a one off situation. Thanks

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