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Main Area => General GS500 Discussion => Topic started by: gsmetal on July 28, 2007, 05:24:06 AM

Title: Fuel Petcock Question
Post by: gsmetal on July 28, 2007, 05:24:06 AM
Can anyone recommend a cheap place online to purchase a fuel petcock for a 91 GS500?

I think mine is toast as I'm not getting proper fuel delivery at highway speeds.

I also remember seeing something about inproper vaccuum and to purchase a petcock that gets around this.

Can anyone give me some direction?
Title: Re: Fuel Petcock Question
Post by: ohgood on July 28, 2007, 06:26:35 AM
You can run the bike on "PRIME" when you're traveling at high rates.

Here's the search link for 'petcock' it should show other's progress. http://gstwins.com/gsboard/index.php?action=search2 (http://gstwins.com/gsboard/index.php?action=search2)

Starvation is a real PITA. I just switch to PRIME whenever I see a 55 mph speed limit sign and leave it there till I stop.
Title: Re: Fuel Petcock Question
Post by: Trwhouse on July 28, 2007, 06:37:31 AM
Hi gsmetal,
Yes, fuel starvation is a common problem on our bikes.
I have a 1991 GS500E and had the same issue, which was fixed by replacing the stock fuel petcock with a new OEM unit.
I bought mine at a mail order Suzuki dealer in western PA near Pittsburgh for about $30 less than my local dealer, even after shipping was added.
Try this place at 1-800-860-0686. I was very happy with their service.
If you search the GStwin.com site, others have fixed their existing old petcock by turning it into a NON-VACUUM petcock, which gets rid of the vaccuum problems entirely. This is done by using JB Weld in a tube to block the old vacuum portions of the petcock so that it now becomes a manually-operated fuel petcock, eliminating the weak operation of the vacuum system.

Here's one person's link who did this modification:
http://gstwins.com/gsboard/index.php?topic=19363.0

Here's a photo of what they did and what they plugged:

http://www.bbburma.net/Temp/Jenya_petcock_plugged.jpg

The next time my bike ever has the fuel starvation problem, this is the route I'll take, using the JB Weld and fixing the problem for good. I kept my old petcock and will modify it using this technique at some point.

I hope this helps.

Best wishes,
Todd
Title: Re: Fuel Petcock Question
Post by: frankieG on July 28, 2007, 07:13:50 AM
i have one that i am not using, let me know if u need it.
Title: Re: Fuel Petcock Question
Post by: PatrickInNC on July 28, 2007, 07:26:01 AM
I too have one if you need it off my 91. Brand new.

I just switched to the Pingel set up like what is outlined in the racers section. It makes things soooo much easier, and is great if you do alot of tank removal.
Title: Re: Fuel Petcock Question
Post by: Jughead on July 28, 2007, 08:03:01 AM
Yeap Ditch the Stock mess and go to a Pingle.You will have to widen the Hole in your tank to Accept the Petcock Filter but you'll be able to get rid of all of those Hoses. :thumb:
Title: Re: Fuel Petcock Question
Post by: gsmetal on July 28, 2007, 08:14:25 AM
Well switching the petcock to PRI doesn't help - I still get this massive hesitation when I get on the gass at highway speeds.

I'm not sure switching to a new petcock is the ansewer but I'm running out of ideas

It's clearly not getting fuel and I'm running out of ideas.
Title: Re: Fuel Petcock Question
Post by: Trwhouse on July 28, 2007, 08:19:13 AM
Hi again,
It also could be a clogged fuel tank cap breather.
Take it all apart and clean it carefully -- the gas cap that is.
There is a tiny ball bearing and spring -- used as a check valve -- so be sure to take it apart on a towel and be careful not to lose anything. You'll need a bit of grease to hold it together while you reassemble it.
You also might think about taking your carbs apart, cleaning everything and replacing all of your old stock fuel hoses.
There could be dirt or clogged lines affecting the fuel system.
One by one, these items have to be done to find the problem.
Good luck,
Todd
Title: Re: Fuel Petcock Question
Post by: trumpetguy on July 28, 2007, 12:39:53 PM
Double check the fuel petcock on the bottom of the tank.  If it is not fully open, it doesn't matter WHAT the other petcock does.