I have a 2004 GS500F. Engine runs fine in prime and doesn't die, when I leave it on ON, it dies everytime. I had the carbs completely went through and dipped. Jets cleaned etc. Took the petcock off my buddies 2009 GS500F, put mine on his. His never died and we road it for a while. I am not sure where to go next. It starts fine, runs fine but it will die if it is out of prime. Any suggestions?
Which petcock did you put on your buddies bike. The tank, or frame?
Sounds like you aren't getting good vacuum to the frame petcock. Check the vacuum hose, replace as needed.
The frame petcock that has ON, Prime, And RES on it is the one I swapped. I agree it sounds like a vacuum leak. All the hoses around the carb look good. Should I just replace all of the vacuum lines and see if that does anything?
You could test the vacuum, but if the carbs were just gone through, and your sure everything is hooked back up right, then
Yes, or replace the petcock with a manual one from a honda dirt bike, slight dremmel work required.
Okay I fixed it with the Vaccuum hoses. It now runs fine! But it sometimes will spike to 3k on the rpms and won't go down unless you put it into gear. I have the idle set to around 1400 when it's fully warm. Not sure why it's doing that. Sounds like air to fuel ratio is messed up or something?