Gas too fancy or narrowly avoided immolation?

[puftas]

was chasing a slow carb leak on my BS38's, and found these. The two aged ones have been on the bike for maybe 5 months max. The clear one is what they looked like before they went on. Plastic is clouded, yellowed, and even bendy and flexible (unused ones are not any of these things). like either heat or chemically weakened. I don't remember, but I think these came from Mike's a while back, and I've used them before without noticing this issue.

Might be heat damage, or possibly the gas I'm using? I run premium, 91 or 93. Is that a possible?

or did I route these things really terribly and only avoid bursting into flames on the highway through sheer luck? I cross routed my fuel lines, and I think the filters were touching the top of the carbs?

Any advice appreciated. I'm a bit freaked out.

 

[Raymond]

Might be the effects of ethanol? Friend of mine bought clear plastic float bowls to set the fuel level on his old 1979 BMW. They discoloured and became opaque in short order. Returned them whence he bought them - the dealer said he thinks it's the E10 fuel what done it.

 

[Adamc]

Raymond's assumption is probably correct.
I prefer to use metal or metal/glass filters like these:

 

[Downeaster]

Another vote for that effin' ethanol here. I've seen a lot of things turned to snot by it.

 

[Jan_P]

Another vote for that effin' ethanol here. I've seen a lot of things turned to snot by it.

Yes Sir
That Ethanol sounds more and more like a horror story -- plastic turning yellow like that takes 30 years otherwise and on top of the carburetors not so warm
Good information Adamc # 3 has it

 

[Mikey]

I bought a bunch of the cheap ones like that out to the garbage they go
I also bought a couple of Visu 90 degree plastic filters which hopefully will hold up
Around here getting non ethanol free gas is easy so that helps too

 

[jetmechmarty]

I assume those are not VISU FILTERS. Rather those are cheap knock-offs. I have a pair of Visu Filters on my XS1100 for several years. They still run clear. Crap like what’s pictured is criminal to put on the market IMHO. Someone could suffer serious injury.

 

[TJZ662]

Any thoughts on these types of filters? I got them on a spare set of carbs I lucked into

 

[jetmechmarty]

Any thoughts on these types of filters? I got them on a spare set of carbs I lucked into

That’s a very similar element to the Visu Filter. It should be fine. The advantage of Visu Filter is that you can see fuel flow. Now, we have to be wary of knock-offs.

 

[Adamc]

Any thoughts on these types of filters? I got them on a spare set of carbs I lucked into[/QUOT

Thats an anodized version of the aluminium one I put an image up of.
The filters are removable for cleaning or replacing, if you can still get them; the body is reusable.

 

[jetmechmarty]

BTW, MikesXS sells VISU Filter and another they describe as “throw away”. It would be good to get a positive ID on the junk.

 

[gggGary]

Had some of those cheap ones quickly do that with premium gas. FWIW I almost never use external fuel filters;
A. if it's fine enough to pass through the petcock filter it'll go through the carb jets too.
B. every filter adds resistance to fuel flow. You are working with less than a foot of head.

And that's without ANY flow resistance from fittings screens turns etc.
Add in high temps (ever seen your gas tank boil?) and even if you have a bit of flow, vapor lock is easily an issue.
We will often be working with LESS than 6" of head.
One of my favorite pics.

There is nothing wrong with that filter, it's not plugged up, just an example of low head (pressure) flow resistance.

You DO clean out your gas tank, right?

 

[Mailman]

Recently when I was working on my bike in the garage, I turned on the gas and it started leaking gas all over the floor. It turned out to be one of my cheap EBay filters that I had bought , it developed cracks and was leaking badly.
I’m sure happy I didn’t have that happen 100 miles from home! I removed them all together.

 

[DogBunny]

While we are on this subject, take a look at what ethanol has done to puftas' and Mailman's fuel lines. Shrunk them, and made them hard and stiff. I assume that they are using the same knock-off "Tygon" fuel line that I used to use and is all over eBay. Eventually, after a few years, it will crack and leak -- happened to me.
Real Tygon comes in a lot of flavors, so make sure you get the ethanol resistant kind. It costs more, isn't always that easy to find, but is worth it.

 

[puftas]

Wow. Well I felt better about my routing and temps until Gary mentioned that gas can boil. Jesus. I realize that's not 212 degree boil, but you may have just sold me on e-bikes (kidding)

Much thanks everyone. I will probably be running a fresh pair of these for a week (short a second vehicle right now), and then replacing them with something better. Thinking I'll follow Gary into the GGgreat beyond of filterless lines, (I've never found even a speck in the inline filters, so logic holds). But I need to do some serious tank self-reflection (cleaning) before I'm up for that. I have put off cleaning and coating my tank (leaving open tanks and battery chargers in well ventilated places is somewhat difficult in NYC), but the power of Forum-dad shaming is strong. Until then glass/metal filters seems a good option.

Just checked my photo roll, I installed those filters in early June, so 4 months. #science. Will be watching my ethanol consumption much more closely from now on. #keto

 

[puftas]

found the SKU:

Bought a 10pk years ago before the "spend a few bucks more" modicum had really sunk into my psyche. Interesting note: the arrow on them specifies the opposite flow direction of any other filters I've used. Maybe should have been a tipoff.

sorry Mikes. And yes, selling these seems not safe.

 

[puftas]

While we are on this subject, take a look at what ethanol has done to puftas' and Mailman's fuel lines. Shrunk them, and made them hard and stiff. I assume that they are using the same knock-off "Tygon" fuel line that I used to use and is all over eBay. Eventually, after a few years, it will crack and leak -- happened to me.
Real Tygon comes in a lot of flavors, so make sure you get the ethanol resistant kind. It costs more, isn't always that easy to find, but is worth it.

Yes. thanks this would explain the discolor. Replaced those lines in June too. Nowhere near as pronounced as the filter degradation but still significant. Bought the tubing off Amazon as well.

 

[Mailman]

I found this website interesting, if you are interested in really understanding fuel filters, the materials they’re made of , and also some information regarding fuel lines. This is well written and informative. It seems for alcohol blended fuel , the see through plastics are probably not the best choice.
https://www.industrialspec.com/about-us/blog/detail/plastic-fuel-filter-body-materials
Here is just one excerpt,

 

[gggGary]

Local small equipment dealers sell Oregon branded tygon by the foot.

 

[YamadudeXS650C]

Had some of those cheap ones quickly do that with premium gas. FWIW I almost never use external fuel filters;
A. if it's fine enough to pass through the petcock filter it'll go through the carb jets too.
B. every filter adds resistance to fuel flow. You are working with less than a foot of head.

View attachment 199562
And that's without ANY flow resistance from fittings screens turns etc.
Add in high temps (ever seen your gas tank boil?) and even if you have a bit of flow, vapor lock is easily an issue.
We will often be working with LESS than 6" of head.
One of my favorite pics.
View attachment 199563
There is nothing wrong with that filter, it's not plugged up, just an example of low head (pressure) flow resistance.

You DO clean out your gas tank, right?

This is very interesting information, Gary.
I run extra filters on 3 of my four XS's, just to be extra careful.
My '75 has for 2 years has had a slight glitch, a tendency to stall occasionally at idle after it has run for more than 45 min.
I've thoroughly sorted out the carbs.
It has the external filters, and a new (NOS) tank, so the internal filters are clean.
I've considered changing the high output coil I got with the PAMCO, as a possible source of the problem.
But I'm now thinking that it might be having a bit of fuel starvation (as you describe) when hot.
So I'm considering eliminating the extra filters for awhile to see if it cures the glitch.