Kx250f won't full throttle

Seems like it's running out off fuel at top end I've lifted the needle messed with airscrew and makes no difference been told to fit boyesen hot shot does anyone recommend it or is it more for bottom end improvements , engine has had top end rebuild and new head which has been ported etc as far as I can make out other than that it is stock

Did it ever run well?

If so it's not the jetting.

WOT is not the fuel screw (that is for idle)

Not the needle (that is for midrange)

Not the AP (that is for low to mid range acceleration)

Not sure where you are getting you advice from but I'd run quick as you can away from it.


WOT is the main jet, if it is the main jet. It can also be a bad spark plug, coil, stator or other electrical malfunction.

Worn out cam chain, bad valve springs

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