Bike died on the interstate......?

[offcamber]

Was riding yesterday on then interstate and decided to open it up a bit. Top gear, full throttle up a slight grade hit about 90mph. Then the bike started acting like it was running out of fuel. I just filled it the night before. Got it to the shoulder...then it shut down completely. Would not restart, flipped the petcock to prime...started right up. Seemed to run ok....flipped the petcock back to run....ran the rest of the day with several stops just fine. ....

So what happened?

[s10nova]

vapor lock maybe...i dunno, i had some issues with my bike dying around after driving 15 miles..then i saw the fUEL LINES WERE Routed wrong, ...check that..but probably not your problem with the newer bike

[Homer]

petcock

[SlimKlim]

What year? From what I've heard the GS500E petcock's vacuum system was a little under-engineered. The vacuum is there so that when you shut off the bike in the run position, it automatically shuts off fuel so that if your carbs were to fall apart or something whilst parked, all the fuel won't run out into your garage (or something). However, this vacuum system had some issues at higher speed, causing the bike to act like it was out of fuel. Which sounds like it happened to you. When you turned it to prime you bypassed the vacuum and let the fuel gravity feed into the carbs again.

Also, from what I hear, there are two ways to address this, one is to pull the vacuum line and plug it on each end, allowing the fuel to gravity feed all the time, but removing the ability to shut the fuel off at the frame petcock. Or, you can upgrade to an 01(?)+ petcock which was redesigned to avoid the starving issue. Or maybe it was 04+ I'm not sure. I'm tempted to see if I can find a generic on, off, reserve aftermarket one so that I can just add a step to my  start up procedure and know 100% whether or not I'm going have fuel when I want it or not, when I don't.

[Homer]

You have all that, Klim. 
All I did was this:
http://gstwins.com/gsboard/index.php?topic=19363.0
(Which should have been stickied a long time ago   )

PRI is on, off is off, and reserve is reserve. 
The in-tank petcock stalk was eaten by the pre-treatment for sealing the tank, so the Veypor was programmed for a "2.6 gallon" tank.  That way, when the Veypor says you're empty, you still have fuel remaining. 

[offcamber]

It's a 97, sorry should have mentioned that. Looks like I'll look for a late model petcock.

[mister]

It's a 97, sorry should have mentioned that. Looks like I'll look for a late model petcock.

No need to go hunting for a new petcock unless you know what the problem is. And so far, you don't. It certainly Might be the petcock, could be the breather line in/out of the tank too. Could be a slightly bent fuel hose. Turning it to prime and it worked could have just been a coincident.

Michael

[kaze11]

same happens to me     i went out to get a new helmet with my bother  and hit the highway top gear sprint for a few miles keepin up withb his r6 and  bike just started chugging   so flipped to pri and was fine   but i just converted it to run without vacume and its fine

[SlimKlim]

^ Oh sweet! That takes care of that.  

I'm making good progress this weekend. Tank is primed, most of the non-engine parts are in. Gaskets and seals come middle of this week. Painting tomorrow is a possibility.  

If the parts come in and I the painting gets done (I don't want to rush my color decision) I might pull some real late nights this week and get the motor rebuilt and be crusing around on it. But at this point, id rather get it all the way I want it than try to slam it all back together.

[007brendan]

Definitely sounds like the petcock fuel starvation issue.  I've had that happen to me a few times on the highway, too.  I run my bike on prime all the time now.