O ring replacement cross over tubes

[Little mate]

We'll after cleaning bench testing tuning and syncing the carbs bike ran flawless,until the tune between 1 and 2 started to leak bad, so I'm back into the carbs again. It not like it's my first rodeo,I've been into these carbs more times than I can remember, and a host of other peoples carbs with no complaints. I replaced all the o rings just a couple of years ago, I think it moved a little when I was fixing the choke. We'll it's time to get started should have them on the bench in under 30 mins.

[Little mate]

We'll carbs are on the bench, and I'm getting slower as the years go by.

[whatscooking]

What O rings did you use before?

[Little mate]

We'll rack is split now so will replace all the o rings and put back together wednesday night.i used a kit of ebay

[daves79x]

I've had the O-rings in the Keyster kits fail after a couple of years. That was quite a while ago before this ethanol thing and Viton rings were popular. Viton seems the way to go now with the gas we have.

Dave

[EMS]

It is hard to say.
Viton lately seems to be heralded as the "do-it-all" material. Actually, the only advantage it has, are its temperature capabilities.
And then it really sucks at very low temperatures, where it loses its flex almost completely. Not a concern with a motorcycle application, I think.
Resistance to fluids and chemicals of polymers is a complex issue and O-ring and seal manufacturers refuse to give the O.K. for use without specific testing.

[tevan]

It is hard to say.
Viton lately seems to be heralded as the "do-it-all" material. Actually, the only advantage it has, are its temperature capabilities.
And then it really sucks at very low temperatures, where it loses its flex almost completely. Not a concern with a motorcycle application, I think.
Resistance to fluids and chemicals of polymers is a complex issue and O-ring and seal manufacturers refuse to give the O.K. for use without specific testing.

Are you saying gas with ethanol has the same effects on reg. oring as well as viton orings??

Terry

[EMS]

Are you saying gas with ethanol has the same effects on reg. oring as well as viton orings??

Terry

No, Terry. I am not saying that. I say I don't know. And I am skeptical about Viton being the solution to everything.
I am not aware of any data that shows Viton's resistance to alcohol is superior to that of HNBR or NBR

[tevan]

I would love to see results on both orings side by side. Both in ethanol blended 10% gas. Anybody seen any of this on the web? A true test.

[hondaman160mph]

The real problem is the BS propaganda the public has been told about ethanol blended fuel.
Factor in the amount of water and fuel it takes to produce a gallon of ethanol and the only benefits are to the ethanol producers.
The following is from DuPont, the producers of Viton
DuPont™ Viton® fluoroelastomers have been successfully used in seals and hoses for automotive fuel systems for over 45 years. Viton® has been shown to have broad compatibility with petroleum-based fuels and is a preferred elastomer for today’s sophisticated fuel injection systems.

DuPont and several leading fuels system OEMs have extensively tested different compounds of Viton® elastomers in pure ethanol, ethanol blended with hydrocarbon fuel, biodiesel, biobutanol and alcohol-based blend fuels.

The results indicate that fluoroelastomers offer the best permeation performance of traditional elastomeric sealing materials. Among the most dramatic findings, Viton® has been shown to be 1,000 times better than silicones (VMQ) and 100 times better than HNBR (hydrogenated nitrile butadiene rubber) in permeation resistance. It also has better heat aging and compression set resistance performance than either VMQ or HNBR.

Viton® elastomers also demonstrate excellent compatibility with biodiesel, and with ethanol; high resistance to permeation and chemical attack by alcohol, pure ethanol and blends of ethanol with hydrocarbon fuel; long-term retention of critical properties in current and emerging biofuels, and outstanding low temperature (-50°C to -65°C) static sealing performance in biofuels, (also at elevated temperatures).

DuPont™ Viton® fluoroelastomers (FKM) provide fuel permeation performance to meet new environmental regulations such as US CARB LEV II, EPA Tier II and PZEV, and European Euro 5. Viton® has long-term aging and compressive stress relaxation (CSR) performance to meet the 15-year life requirements — offering good low-temperature performance and excellent heat and compression set resistance when compared to traditional gasket materials such as HNBR and VMQ.

[EMS]

There we have it! Propaganda from Dupont!

[Rick Pope]

The real problem is the BS propaganda the public has been told about ethanol blended fuel.
Factor in the amount of water and fuel it takes to produce a gallon of ethanol and the only benefits are to the ethanol producers.

Like most folks, you're overlooking the whole point of ethanol in our gas. It brings oxygen to the party, thus reducing emissions. Gov't regulations and all.......

All things considered, I'll gladly trade clean air for some carb issues in antiques. The vehicles we use most don't mind the ethanol.

[Larry Zimmer]

For the little total cost difference, go with Viton. If you plan to ride at -20 deg F (or less), let me know. I'll find you another material recommendation!

[Little mate]

The o rings did not show any signs of deteriation,but the area around them was loaded with ethenol residue. Looked like 10 years of crud but it's only been 3 or so years since I replaced them.

[EMS]

Like most folks, you're overlooking the whole point of ethanol in our gas. It brings oxygen to the party, thus reducing emissions.

..and you really think that's the reason we have ethanol in the gas, Rick??