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Ethanol Tank Swelling

Resom

Just got it firing!
Joined
Jul 15, 2014
Messages
12
Location
Los Angeles
The modern day USA issue of our tanks being destroyed by our Government..!

Has anyone with a newer Stelvio NTX (2012 or newer) had issues with their Stelvio tank swelling or developing "bumbs" from the ethanol (10%) that we're forced to run in the States? If so, has Guzzi resolved the issue as other Italian manufactures (Ducati, MV Agusta) have?

MV Agusta (Acerbes) actually has a new formula of plastic that resists ethanol. Ask me how I know. :) This new tank material didn't come out until 2015 though. I'm wondering if Guzzi has also resolved the issue..?

Cheers!
 
Have a 2012 and have never had the issue. We get the same fuel as you do. I try to find Ethanol free premium when I can but Shell is now the only company that has it (at least here). Would have to say after 50,000km the bike has had probably 20% ethanol free and the rest up to 10% ethanol.
 
My 2007 Griso (bought new in '06) has had 10% ethanol gas its whole life. No issues yet.
The wifes V11 developed some pimples, mainly under the strapping that holds the tank bag on. It appears that the fault lay with Acerbis for making the tanks out of a plastic that was not 100% suited for the job and / or defects in the tank. Why is that the governments fault?
Either use a plastic that is 100% fuel resistant or make the tank out of metal. It really is that simple.
 
Quote: Why is that the governments fault?

A better question is, why are we forced to run ethanol by the Government? It has been proven that it's worse for the environment in more way than one. It has been proven that it destroys small engines and fuel systems. Shall I go on?

If you don't know the answer to the question, you need to do some reading.
 
I'm sorry. I thought this was a thread about fuel tanks and whether or not they are compatible with modern ethanol containing fuels.
If this is a political rant I'm out.
 
Some of the early Norge, and I believe Griso tanks, had some issues. I have never hear about it on anything past about 2010. I suspect they have found better coatings for the tanks.
I assume metal is out, because it is too expensive to make the complex shapes that they like to use today. Too expensive to get steel stamped like that, but easy to mold a plastic tank into odd shapes.

I'm not 100% convinced that it is fuel additive related. Keep in mind that 30 years ago there were almost no plastic tanks being used, So you can't just say that '30 years ago fuels didn't do this'. Of course, we may have been discussing cracked seams in the metal and rusting, back then. :D
 
Well, I thought I got lucky with my 2014 Griso, but it has started to develop blisters about .250" in diameter. I thought Guzzi tanks were "thick" enough to resist the damage caused by Ethanol. That's why I'm asking about the Stelvio.... I haven't heard of anyone's Stelvio having issues with his/her tank.

When I bought my Griso, the dealer said he hadn't seen any issues with the Griso tanks, but now he's singing a different tune, saying he is starting to see Griso tanks with issues, but still no Stelvio's. Strange, huh?

I have several MV's that have had the issue, but for 2015 Acerbes came up with a new plastic formulation which works. I had one tank warrantied and it was marked with an "E" for Ethanol, I was told. It hasn't warped as of yet (knock on wood).

Maybe it's hit or miss with the Guzzi tanks, depending if there's a "thin" void in one tanks molding as compared to another....?

Still, no one has seen or heard of a Stevio with blisters or warping...?

Thanks!
 
Got a friend with serious tank swelling and bubbling on a 2006 1200 Sport but touch wood no problems so far with either my 2011 Stelvio or my 2006 Griso. In the UK we are mostly still on 5% ethanol although I believe the 10% stuff is on its way. Had tank swelling problems with my old Triumph Sprint 955 that also had a plastic tank made by Acerbis.
 
Well, I thought I got lucky with my 2014 Griso, but it has started to develop blisters about .250" in diameter. I thought Guzzi tanks were "thick" enough to resist the damage caused by Ethanol. That's why I'm asking about the Stelvio.... I haven't heard of anyone's Stelvio having issues with his/her tank.

When I bought my Griso, the dealer said he hadn't seen any issues with the Griso tanks, but now he's singing a different tune, saying he is starting to see Griso tanks with issues, but still no Stelvio's. Strange, huh?

I have several MV's that have had the issue, but for 2015 Acerbes came up with a new plastic formulation which works. I had one tank warrantied and it was marked with an "E" for Ethanol, I was told. It hasn't warped as of yet (knock on wood).

Maybe it's hit or miss with the Guzzi tanks, depending if there's a "thin" void in one tanks molding as compared to another....?

Still, no one has seen or heard of a Stevio with blisters or warping...?

Thanks!

Until just now I hadn't heard of it on a Griso.
Early Stelvio's have a separate tank and outer skin, so they were good. Now the tank is the painted skin.
 
Until just now I hadn't heard of it on a Griso.
Early Stelvio's have a separate tank and outer skin, so they were good. Now the tank is the painted skin.

Yeah, I spoke with my dealers parts guy last night... He said he's starting to see Griso tanks come in on warranty, mainly from blistering (same as mine). He said he hasn't seen any Stevio's (yet). I wonder when Guzzi will start using the same plastic as MV Agusta..? I imagine they already are, but it will take some time to flush the old tanks thru the system, especially the ones in their Spares warehouse. I think I'll wait until next spring to file a claim against my Griso tank, hoping that all the old tanks will be flushed thru their parts inventory by then.
 
I never had a problem with my '09 Stelvio tank, it had ethanol for 5 years and 55,000 mi. I had a Stucci aux tank that I couldn't keep sealed around the fuel pump, do to ethanol I believe. Ducati still can't solve the problem on the Multistrada.
 
MV Agusta (Acerbes) actually has a new formula of plastic that resists ethanol. Ask me how I know. :) This new tank material didn't come out until 2015 though. I'm wondering if Guzzi has also resolved the issue..?

Cheers!

When did our government start allowing street motorcycles to use plastic gas tanks? I was under the impression that street bikes must have metal tanks.
 
We had a Buell X1 and a Blast, from 1999 and 2000 respectively, that had plastic tanks.
Never had an issue with them and they always had ethanol fuel in them.
 
As the owner of several bikes in the U.S. that have plastic tanks, including two Ducati and a V11, I'll add what I know about plastic tanks and ethanol. The plastic tanks on European motorcycles are made by Acerbis, an Italian plastics company. They are made from a type of plastic known as PA6 nylon. If you look inside your fuel tank, its a white plastic. The manufactures love it because it holds glossy paint so well and can be molded into complex shapes. If your bike has a painted plastic tank (not a shell, or cover) you can be certain it is PA6 nylon and (sooner or later) WILL be affected by ethanol in the fuel. The tanks are "roto-molded" meaning they pour liquid plastic into a mold, and then rotate it like a chicken on a rotisserie to coat the inside of the mold. Once again, shine a flashlight into your tank and you might see small drips and runs like candle wax, from this process. This can and does lead to varying wall thickness which explains the bubbles and blisters that appear. PA6 nylon is "hygroscopic" meaning it absorbs water. This is what leads to the expansion and deformation of the tanks over time. I think I read where PA6 nylon can absorb up to 10% water by volume. Every used Norge I've looked at shows some swelling, which can be seen by turning the handlebar to full lock, and the top triple clamp will come into contact with the tank before it hits the metal stop. There are usually two small chips in the paint at the front of the tank where this happens. Since the amount of moisture the plastic absorbs is limited, the swelling does stop. Your tank won't grow forever, like some tumor! But getting the mounting holes to line up after the tank has been removed for service can be a real pain sometimes. The manufactures have slowly phased out some (but not all) PA6 plastic tanks for a different material, black in color, which will not hold paint, hence the trend to fake plastic "covers" over the tank on many bikes. Hope this long-winded explanation sheds some light on the subject.
 
The manufactures have slowly phased out some (but not all) PA6 plastic tanks for a different material, black in color, which will not hold paint, hence the trend to fake plastic "covers" over the tank on many bikes. Hope this long-winded explanation sheds some light on the subject.

My Dorsoduro had one of these black tanks with side covers attached. If it was in any better than the previous PA6 tanks, it was not noticeable. Each side cover was held on by three bolts. After about 18 months, getting the covers back on was a challenge (the holes didn't line up anymore). The tank grew about an inch in length during the same period. The mounting bolts on the front went through slots in the tank, but that was quickly eaten up and not sufficient to account for the expansion. I found myself having to use a 2x4 to pry the tank to get the rear bolt in. I've read where others used straps and clamps around the tank to get it back on. Apparently, you might even get lucky if you put it in a freezer overnight.

Insanity.

And one of the reasons I bought another V7.
 
Yes, I didn't want to ramble on, but it seems the newer "black plastic" tanks have issues as well. All plastics expand to some degree, even if it is just thermal expansion from sitting in the sun on a hot day. This growth needs to be accounted for when the manufacturer molds the covers, mounting slots, etc. I've read that Ducati's MTS1200 Mutlstrada fuel tank will expand slightly, pushing the painted plastic panels out of position. Harley's short lived XR1200 had a plastic fuel tank and painted cover. The tank would expand and pop the cover loose! Harleys solution was to make a smaller capacity fuel tank so there was "space" for it to expand under the painted cover. Ducati is still the worst of the lot, their "fix" is to send you a new tank made of the exact same plastic as the old one...shameful.
 
I've run nothing but E10 in my 13 Stelvio. With over 41k miles the tank remains perfect.
 
I avoid the e10 fuel like the plague, but it's only because the mileage seems to be so much worse from it. Same with the biodiesel. Yeah, they're cheaper, but you have to fill up more often.
 
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