What caused this?

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N0rt0nelectr@

N0rt0nelectr@

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The petcock on one of my bikes started to leak, so I drained the tank and pulled the petcock. This is what I found. Not sure what caused it, ethanol maybe? There are after market petcocks and I don't remember when or from whom I got them.
Ideas?

John in Texas
What caused this?
What caused this?
 
Perhaps condensation in the tank lead to excessive water contamination of fuel, Ethanol-laced or not, which lead to corrosion of the gauze mesh. That green colour on the remaining areas is how copper oxidizes. So partially filled fuel left in tank, esp. over winter months in unheated location, gets too much moisture content leading to corrosion. How does the inside of tank look, esp at the level of the petcock filter pipes?
 
that's a nasty mess ! .... also which tap is your main and which is reserve , usually a little tube inside main strainer to add height so you have to switch over to reserve tap to source last of your fuel from tank ? .... those taps look identical
 
I run reserve on both sides, with the hump in the bottom of the tank there is still some spare on one side.
Mind you mine is an interstate, i deserve to walk if i run short of fuel on one of those.
 
Reserve gets all your fuel but it is also low enough to get any sediment too.
One of my big complaints is no trip meter on the speedo. Sure you can replace it
and I have on my other brit bikes and suppose I should on the Norton as well.
Why? Because trip meter is your fuel gauge remembering what the numbers were
on fill up will do if you can remember!
 
Craig said:
that's a nasty mess ! .... also which tap is your main and which is reserve , usually a little tube inside main strainer to add height so you have to switch over to reserve tap to source last of your fuel from tank ? .... those taps look identical
Click to expand...
I have an Interstate and run 2 reserve taps, otherwise there is a fare amount of fuel left on the side where the main tap is.
John in Texas
 
Tornado said:
Perhaps condensation in the tank lead to excessive water contamination of fuel, Ethanol-laced or not, which lead to corrosion of the gauze mesh. That green colour on the remaining areas is how copper oxidizes. So partially filled fuel left in tank, esp. over winter months in unheated location, gets too much moisture content leading to corrosion. How does the inside of tank look, esp at the level of the petcock filter pipes?
Click to expand...
You might be right, I was down for some time after knee surgery, I will remove the float bowls and inspect. Thanks for the tip.
John in Texas
 
Tornado said:
Perhaps condensation in the tank lead to excessive water contamination of fuel, Ethanol-laced or not, which lead to corrosion of the gauze mesh. That green colour on the remaining areas is how copper oxidizes. So partially filled fuel left in tank, esp. over winter months in unheated location, gets too much moisture content leading to corrosion. How does the inside of tank look, esp at the level of the petcock filter pipes?
Click to expand...
Or are these cheap far eastern fuel taps?
 
Is it simply the ethanol in fuel these days or is there something else in the mix that causes all this mayhem?
I'm still in morning for my melted fastback tank!
 
I am having a hard time relating as to how ethanol can "eat" copper gauze. A low (acidic) pH can do that. What can cause a low pH in fuel?

Slick
 
+one on the two reserve taps. Both on. Just keep a close watch on fuel level. Only ran out of gas once in 20 years.
 
Me too ! .... before I had work flip phone (okay maybe more than 20yrs) , was a very long walk and missed an afternoon of work and lunch ... put heat shrink on reserve tap lever as reminder not to touch ....
 
baz said:
Is it simply the ethanol in fuel these days or is there something else in the mix that causes all this mayhem?
I'm still in morning for my melted fastback tank!
Click to expand...
I think ethanol gets blamed for all sorts of horrors, some justified but many not and those maybe a generalised bias from an anti climate change stance.

Ethanol does absorb water from the air. But so does gasoline to some extent. Ethanol does have a weak solvent effect on some types of rubbers and plastics. But same can be said for other additives in fuel such as cleaners, emmission related additives and winterization products.

The petcocks in this thread seem to have a copper mesh screen. Copper will oxidize in conditions where moisture is present. That's why I suspect the tank was left partially filled over long periods and likely cold temps. Perhaps over many years. I don't think this is something folks need to fret over if they are diligent about taking preventative steps.
 
Bernhard said:
Or are these cheap far eastern fuel taps?
Click to expand...
Perhaps. But if copper mesh is the standard used in most setups then I'd think they all would suffer same fate. My clear plastic external filters use what appears to be a stainless steel mesh. So that could be employed for petcock pre filters too.
 
A brazed after-market tank may have been brazed with a copper alloy. Don't know if that oxidizes green or even can corrode off in small parts that are too big to get through the filter. It really looks like the filters or something made fine enough to disintegrate. Did you try scraping some off the filter and putting that on the tip of a steel nail to see the color of the flame holding it over a gas burner? Probably green in the flame, but if not, even that's a clue.
 
Onder said:
Reserve gets all your fuel but it is also low enough to get any sediment too.
One of my big complaints is no trip meter on the speedo. Sure you can replace it
and I have on my other brit bikes and suppose I should on the Norton as well.
Why? Because trip meter is your fuel gauge remembering what the numbers were
on fill up will do if you can remember!
Click to expand...
The Vaguelia clocks fitted to the later Interstate have trip meter, but the clocks are not the same quality as the Smiths.
 
texasSlick said:
I am having a hard time relating as to how ethanol can "eat" copper gauze. A low (acidic) pH can do that. What can cause a low pH in fuel?

Slick
Click to expand...

I doubt the screens were made of copper, but rather a copper alloy. Bronze is much more noble than yellow brass. I'm not sure what in the fuel would have acted as an electrolyte (like salt water) but galvanic corrosion will attack the zinc in yellow brass and leave nothing but copper cheese. My guess is these were made with cheap yellow brass.
 
kommando said:
The Vaguelia clocks fitted to the later Interstate have trip meter, but the clocks are not the same quality as the Smiths.
Click to expand...


To me a second to resist on the Veglia spelling, by which time I had said Vague Lia to myself! :rolleyes:
 
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