GS1000 Fuel Diaghram O-ring source

[srsupertrap]

Happy Cyber Monday,

My 1979 GS1000 vacuum operated fuel petcock has started leaking gas in the On Position . . . I guess I am lucky I have gotten 33 years of service out of it. I would just like to replace the diagram O-ring depicted in the diagram below. The dimension of the O-ring are as follows:

ID .154"
OD .288"
Thickness: .070"

Any suggestions for a source of this O-ring . . . I have checked Parker.

TIA


















I hoping someone has already resolved this problem.

[1980GS1000E]

Rebuilt petcocks of this type tend leak soon after. Just get a new one. They are available on eBay.

[DPage]

Petcocks seem to be a little touchy to rebuild, unlike a lot of other things on a GS (or so I've read). Some people get lucky on petcock rebuilds, others don't. I got a new OEM petcock online from a Partshark/Boulevard type dealer in 2005, and it cost $42. Well worth it, I expect no failures like carb flooding for 15 years or more. Good insurance for something that could drive you nuts if it goes wrong (gas leaking into the oil, etc.)

[tkent02]

Rocket Seals in Denver has every seal known to man. At least every one I have asked for.

There ought to be a seal place in Springs someplace?

[tom203]

I had good luck with this outfit- confusing layout to navigate

http://www.orings-online.com/o-rings.html

But like others have said,you'd really be better off to just retire this old petcock and not worry about it failing.

[Nessism]

Shouldn't be hard to match up the size at an auto parts store. The Napa in my area has a couple boxes of assorted O-rings to choose from. A viton O-ring will have the longest life.

For those advocating replacing the petcock, discount price is $278. I'd look for an O-ring. http://www.boulevardsuzuki.com/fiche...1978&fveh=2146

[bwringer]

It's a metric o-ring, so you'll have much better luck working in millimeters.

.154" = 3.9mm

.070" = 1.78mm

Allowing for squish-itude and the effects of 30 years under gas... you're likely looking for a 4mm ID X 2.0mm thick or 3.8mm ID X 1.9mm thick.

However, it would be more productive to measure the area where the o-ring is expected to seal. Switch your caliper to mm and measure the OD down in the slot where the o-ring sits, as well as the OD of the outside of the slot.

McMaster-Carr is a great source for o-rings and many other goodies if you don't mind buying a bag of 100. (I'd use Buna-N here, not Viton -- Viton is harder and likely wouldn't seal.)

http://mcmaster.com

And here I will mention, as others have also made clear, that this is most likely not going to work. The other rubber parts are just as tired. But good luck!

[bmac]

o'ring replacement

I have replaced that o'ring on my 450g recently. The petcock was only 5yrs. old. Went to auto zone and they carry a package of o'rings in different sizes in the misc. isle. ( knobs, bushings and whatever section) Found one just a tad larger but still worked well. The metal tang on the inside of the petcock nicked that o'ring putting a small slit in it causing it to leak. The new oring is fatter yet seals well in the inlet for the fuel. Bob

[srsupertrap]

Guys,

I previously replaced all the other gaskets (4 Hole Gasket, Lever O-ring & Rubber Tank Gasket) with Suzuki OEM stuff and they are not leaking. Although I don't know the original size of the Diaphram O-ring, I believe dimensionally it has not changed too much because the only force imparted on it was the wimpy diagram spring. I think it just too hard because it started leaking when getting cold. I agree Buna-N is the correct material choice.

I also checked McMaster before posting and found they carry far fewer metric size O-rings. The closest size I found to my measurements above was a standard size O-ring in the following size

ID .145" (Tighter)
OD .285" (Smaller)
Thickness: .070"

I guess I could try that & report back or like bwinger suggested take measurements of the sealing surface OD. BTW, the sealing surface is concial.

[Nessism]

Steve,

Buna-N is not the right choice, Viton is.

As for selecting the size, you want to select an O-ring that will stretch about .040" when installed over the nipple. Stretch too much and the O-ring will have a short life. Too little and you get a leak.

[rustybronco]

I hoping someone has already resolved this problem.

Yes.

I grabbed an o-ring from our stock here at work. The one I did use had a slightly larger thickness than the original o-ring. I renewed the seat with a dowel coated with valve grinding compound and it sealed perfectly.

http://thegsresources.com/_forum/showpost.php?p=1579857&postcount=8

[1980GS1000E]

I only had to cough up 45 bucks for my replacement petcock.

[Nessism]

I only had to cough up 45 bucks for my replacement petcock.

That's the only advantage of the crappy leverless petcock.

[srsupertrap]

Rocket Seals in Denver has every seal known to man. At least every one I have asked for.

There ought to be a seal place in Springs someplace?

Tom,
I checked Rocket Seals yesterday and low and behold they list a nearly identical metric O-ring with the following dimensions:

ID: 3.9mm (.154")
Width: 1.8mm (.070)

If the math is exact that would make the O-ring OD 7.5mm but there are +/- tolerances not stated. I put in a RFQ on-line and I am hoping the minimum is not a Qty of 1000. Should hear back today what the cost is for Viton & Buna-N and will update once I get pricing.

Were the OEM seals Buna-N (WWI Era) or Viton?

Steve

[srsupertrap]

Steve,

Buna-N is not the right choice, Viton is.

As for selecting the size, you want to select an O-ring that will stretch about .040" when installed over the nipple. Stretch too much and the O-ring will have a short life. Too little and you get a leak.

Just spoke with the Parts Technician, Viton is the correct choice for today's gas with ethanol additives etc.