I just need confirmation that I can utilize the fuel petcock from a 2004 Honda CRF 250X with slight modification on my 89 GS500. Is this correct? Thanks!
This thread has a little information about it, including a picture of this Honda petcock.
http://gstwins.com/gsboard/index.php?topic=36958.20
Honda CRF 250 2004 part no.16950-KSC-003.
The poster in that thread has a lunchbox filter on his bike. That let him mount the petcock in the original position. I put this petcock on my bike and am still using the stock airbox. I couldn't attach the petcock to the original mounting hole, it made the inlets face directly into the indented part of the airbox.
I used a bolt and 3 nuts to attach it to the locating hole just rearward from the mounting hole. I put the bolt in from the back side, so it functions as a stud. I put a nut on it to hold the stud in place, then another nut at the proper distance to locate the Honda petcock, then another nut to hold the petcock onto the stud.
Sounds more complicated than it was, took very little time and I'm very happy with the result. I'll try to take a couple pictures and post them if you want me to.