The bike works on a vacuum fuel delivery system. If you leave the petcock in the prime or reserve position, it will gravity feed fuel into the bowl, and can overflow out the bowl drain tube, particularly if the float isn't set correctly and doesn't shut the fuel flow off.
Normally, you'd have an off position on the petcock, but because it's vacuum fed, if the petcock is in the ON position, fuel will not flow into the chamber if the engine isn't running.
The reserve setting should only be used on your way to the service station, and once you fill up, must be turned to the ON position.
The PRIME position is used to fill the chamber after the bike has been sitting for a while. You turn it to PRIME for a moment or two, then back to ON, then try starting the bike.
Here's a great 30 minute vid that goes through all of the GS500's features:
http://www.youtube.com/watch?v=AzTpSMWFhbY
Good luck and happy biking!
Posted: 04/10/2011 at 21:46
