Protecting the plastic fuel tank from ethanol

Discussion in 'Norton Commando 961 Motorcycles' started by Fast Eddie, Nov 14, 2017.

  1. Fast Eddie

    Fast Eddie VIP MEMBER

    Oct 4, 2013

    Whilst it doesn’t seem very widespread, we have had some reports on here about the plastic fuel tanks suffering from ethanol damage.

    As I will (hopefully) be collecting my new 961 soon, I’d like to ask the collective oracle whether or not it is deemed wise to protect these tanks with some kind of treatment / liner product.

    What are your that’s on this y’all ?
  2. Danno


    Feb 7, 2010
    Ethanol has a different effect on plastic than it does on fiberglass. No dissolving resin, but the whole tank can swell up like a poisoned puppy. A friend with a Ducati 1098 had to have his plastic tank replaced as it swelled so much it no longer fit the mounting bolt locations. He ended up trading it on an 1198 with an alloy tank before the replacement could swell off it's mounts.

    My nephew's Sprint ST plastic tank has also swelled, although the mounting points can still be used because the rear ones are slightly adjustable.
  3. Fast Eddie

    Fast Eddie VIP MEMBER

    Oct 4, 2013
    Exactly what I wish to avoid Danno!

    So, is there a coating for plastic tanks that prevents against this ?

    And has anyone tried it ?
  4. Clive


    Jun 9, 2017
    Ask Clem. He will tell you that the ethanol absorbs water and it's the water that causes the problems. If you store the bike then ideally empty the tank, otherwise completely fill it because it seems to be the air gap/ surface that allows the water in. The only petrol without ethanol seems to be Esso Supreme Plus and that's only in the main part of the UK, ie not Scotsland or the south west. I only fill my new 961 with this and keep a spare can at home in case I need to top it up for a journey. Or start saving for an alloy tank. Ooo nice shiny shiny.

    I was at the launch at the factory on Sunday and the bikes look fantastic.......

    If you need to be reassured about the quality, reliability etc then ask to talk to Skinner. He is a really first rate down-to-earth engineer (and director) who looks after warranty, engineering and improvements.

    Regards - Clive


    Nov 29, 2013
    I always use an ethanol and water fuel stabilization product like Startron or Marine Stabil as recommended by many dealers.
  6. Britfan60

    Britfan60 VIP MEMBER

    Jan 5, 2014
    To ease any pressure build up, if any, leave the cap closed but unlatched. I don't but that would work. I also leave the tank full and gas treated with Startron or Sta bil marine grade (blue) which claim to fight ( I don't think totoally neutralize) the effects of ethanol.
  7. Fast Eddie

    Fast Eddie VIP MEMBER

    Oct 4, 2013
    Thanks guys, it sounds like a stabilising additive may be the way forward.

    I can’t see leaving the cap open helping, surely the tank is vented anyway? And leaving the cap open will surely expose the fuel to more moisture laden air??
  8. richard-7


    Feb 24, 2014
    I just ethanol free fuel and if I cant find any then just a enough to get me to the next station. I have not used stabalizer and it has not been an issue for us canadians.
    contours likes this.
  9. BritTwit


    Aug 25, 2009
    I have never been able to find ethanol free gas in NYC.
    Often the stations listed on the ethanol free sites no longer have it, or they are closed.
    I use Marine Stabil in the tank and it works fine.
    In my bikes with metal tanks I top the tank off to prevent addition moisture from getting in.
  10. LEXngton


    Jul 21, 2017
    This is a pretty good site which lists ethanol-free stations in the US & Canada.

    Lists only 1 station in the city I currently live in and sure enough they do carry ethanol-free gas.
  11. Britfan60

    Britfan60 VIP MEMBER

    Jan 5, 2014
    Its closed but not sealed. If the venting were adequate, the tanks shouldn't warp, should they. I keep my bike covered anyway so....
    No ethanol free near me. All upstate. Not going to do a minimum 2 hour drive. There is however a guy that has 110 octane ethanol free in 100 gallon drum not too far from me @ 10 bucks per gallon. I tank up the old Bonnie with that for winter storage only. BirtTwit....he's around the corner from Billy Joel's bike museum/storage facility in Oyster Bay. His mechanic, who likes to talk and is a great guy turned me on to that place.
  12. BritTwit


    Aug 25, 2009
    I was at Billy Joel's bike museum a few years ago and spoke with his mechanic/designer.
    I noticed a Hinckley Bonneville with 904 kit, 39mm Keihin flat slide carbs, big valve ported head that was there.
    He discussed everything that was done to the bike.
    Pretty awesome twin.
    Britfan60 likes this.
  13. SIC 58

    SIC 58

    Aug 19, 2017
    All good info. Options besides ethanol free gas and responses above - get an alloy tank - pricey.
    Seal it with a product like Caswell in U.S.
    A few YouTube videos on “how to” are entertaining at least.
    My own experience is inconclusive with ethanol.
    Have a Triumph DAYTONA T595 (1998) that had swelling about 2 x 3 inches, that simply went away after 6 months by itself. Have a 1098R with a plastic tank and never any tank distortion.
    Am going to try the Caswell coating on a new bike / tank just to see how it works. My local shop won’t coat tanks as they can flake and cause other problems. There is also a company out there that makes Kevlar tanks that supposedly don’t swell. They don’t make them for all bikes but the price is not as high as an alloy tank. Sorry if I am stating what most readers know.
  14. Britfan60

    Britfan60 VIP MEMBER

    Jan 5, 2014
    RE: 1098 From what I understand is that Ducati addressed that issue and corrected it. Also.....for what its worth...Norton's tanks are fabricated with the same material as Ducs. That could have just been a line from the dealership when I asked about it during the sale. And the Daytona?? Corrected itself?? What kind of stroke of luck is that?? 2 x 3 inches is huge.
  15. contours

    contours VIP MEMBER

    Jan 1, 2012
    Stewart's in VT and NY has an ethanol-free premium. Maybe you don't have those stores near NYC?
  16. BritTwit


    Aug 25, 2009
    Unfortunately the only ethanol free stations are a health distance from NYC.
    Just have to learn to live with ethanol contaminated fuel.:(
  17. jetworks


    Jul 27, 2006
    I've been thru the Ducati Dilema with the sport classic with 2 tanks under the extended warranty/ class action. I'm draining my 2015 as I already had a leak at the fuel pump flange. The tank actually warped about .060 . Being in the aviation field I re contoured the fuel pump flange with sealant we use in the industry an,So far no leaks. The Caswell coating didnt work. I year left on warranty on this beautiful yellow 961 not looking forward to this issue if it persists.

    1973 Norton 750
    2015 Norton 961
    2018 Harley CVO RoadGlide

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