Just what is on the reservoir end? A bandjo or screw-in fitting?
I am working on a friend's KX/KDX hybrid. The existing hose routing is fine with the MX number plate, but if a headlight is added, it needs to be replaced with a longer hose to loop above and around he back, al la KDX, RMX, etc. I'm thinking one from a KDX will work if it has the screw-in fiting on the reservoir end - the existing reservoir has a screw-in fitting and is most likely from a KX, bu we don't know for sure as he is not the creator of this hybrid.