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Some time ago i remember contacting 3x to ask whether the morini fuel tanks were prone to expanding just like some ducati nylon tanks were in the states due to ethanol in the fuel.

The lack of reply probably confirmed that they were keeping mum on the subject.

I've been keeping my eye out for a solution and i see someone now does a two pack coating for sloshing about the inside of a nylon tank. Most of the sealants on the market are for metal or fibreglass tanks not for nylon.

http://www.ebay.co.uk/itm/TRIUMPH-SPEED ... 2ec78a7cf2

At about £40 including postage it may be worthwhile if ethanol becomes more prevalent in forecourt petrol
Certainly cheaper than waiting to find out if the tank has problems bolting down in the original fixings due to expansion.

The only problem would be making sure that the sealant stays in the tank and not on the paintwork whilst applying and making sure that the rim around the filler neck and fuel pump are coated too. (probably a brush coating here, and maybe applying some coating on the tank in case of spillage such as some margerine or similar that can be washed off but would act as a barrier if some epoxy came into contact)

I'd think a template for the openings and some silicone sealant would probably work as you would need to rotate the tank several times to obtain a uniform coating.

What i can tell you that my Granpasso runs bad on the French E10 (Petrol with 10% ethanol)
on my holiday switched to the more expensive 98 and probs where gone

engin stalling, when climbing in to hiher refs hicking
with 98 problems are gone

I now it has nothig to do with tanks just something i noticed a few weeks ago

Super unleaded is the way to go on any bike with a plastic/nylon tank to prevent the swelling problem.

I have just bough a new tank for mine, the original had a crack in the paint when I bought it where the right knee cutout is.

Don't know if crap fuel was the original cause, but have now got a brand new spanker for (relatively) daft money so it will be super/97/98 for me from now on

At present the UK has E5 fuels with 5% ethanol and wouldn't expect too many problems, but this is changing to E10 soon and this may effect things, power will be down and it could lean running depending (but the O2 sensor should avoid that) and yes it could rot the fuel systems.

As you say super unleaded is at present ethanol free, or rather it is at shell and BP garages but not from Tesco which is 5%.

I'm afraid we have to run our engines on food to help American farmers make more money and it helps starving children too. That is it helps them starve which is probably more important.

didn't realise that super unleaded had no ethanol as i just assumed unless it was stated at the pump then there was no ethanol in normal unleaded. Bit of a surprise that.

Fine if you are in a big city, but out in the sticks when touring , not many pumps have super unleaded as it doesn't sell well due to being dearer.

Doe anyone know which italian manufacturer makes the morini nylon tanks .
I think there are two main ones who supply most of the italian bike companies with tanks. But off the top of my head i can't remember there names.

gianni wrote:What i can tell you that my Granpasso runs bad on the French E10 (Petrol with 10% ethanol)
on my holiday switched to the more expensive 98 and probs where gone

engin stalling, when climbing in to hiher refs hicking
with 98 problems are gone

I now it has nothig to do with tanks just something i noticed a few weeks ago

I emailed the factory regarding the E10 fuel GP compatibility but got no response .? Seems like petrol company's are getting more like drug dealers ! Cutting their fuel with this bio crap .notice the Ron rating getting lower too. Some premium is only 97 Ron .

i think the reason you got no reply (the same as i did) is because the tanks are probably made by the same company that made the ducati tanks that were expanding . Plenty of examples in the states where tanks were swapped out and the same thing happened again, due to the tanks reacting to the ethanol.


A bit like Benelli with their z25 gear problems, just don't tell the customer and hope they go away.

The Corsaro fuel tank is made by a company called plastop http://www.plastop.com

Or at least my spare tank date stamped November 2005 was. Unlikely that MM changed supplier for the other bikes or later in the production run but that's a pretty early tank so couldn't rule it out, and can't guarantee of course that the 'new' factory setup are still using the same supplier.

If anyone else wants to check then the plastop logo is moulded on the underside so not too hard to check if you unbolt the front of the tank and hinge up.

Regarding ethanol fuels, only really the tank supplier could say what the material compatibilities are, but there are of course well documented horror stories relating to ethanol incompatibility. The truth of the matter is that E10 is coming, like it or not and the industry has known about it a long time, so there aren't any excuses in my mind for anything built in Europe in the last 5-10 years not being fully compatible with fuels up to E10. Many cars have plastic fuel tanks and should be tolerant to higher than 10% ethanol.

As a fuel I'm not against ethanol at all. Some of its properties make us engineers work harder (cold starting, oil dilution, fuel flow to name but a few) but that should be completely transparent to the end user. Taking it to the extreme of E85 (not that any of us would dare run that in our Morini), the ~30% fuel consumption penalty brought about by the stoichiometric AFR of ethanol is probably the only thing the consumer will notice if the product is engineered properly. I think the intention was to price ethanol fuels cheaper such that the cost per mile was equivalent to normal gasoline, but E85 was available for such a short period in the UK a couple of years ago that I don't know if that happened, and when I've refuelled with it on the continent (in fully flex fuel compatible vehicles of course) I've never paid any attention to the price. The reduced tank range can be an issue depending on the vehicle, certainly I'd not want to be stopping for fuel much more often on the Corsaro on a long ride.

As far as performance is concerned, I have seen up to 5% increased power from running E85 compared with alcohol free 98 RON gasoline, with everything else kept the same (engine hardware, ignition timing, cam timing, lambda, manifold pressure etc). Take advantage of ethanol's antiknock properties, lower combustion temperatures and the charge cooling effect, and the performance gains can be much more; so it is an untruith that ethanol in fuels reduces performance- provided of course that the engine hardware is capable (30% increased fuel requirement can mean injectors become duty limited in some conditions for example) and that the AFR is correctly adjusted for the fuel (either by adaption using feedback from the 02 sensor as adamsson says, or by remapping the stoich AFR or rejetting the carbs accordingly.)

Regarding RON, adding ethanol increases this. I don't know anything about the economies of fuel production but I'd guess that it makes more sense to bring really low RON base stock up to a saleable 95 by using the 5% ethanol permitted, so it wouldn't surprise me if that's what's done with some of the cheaper fuels. I don't think we'll ever know for sure as any gasoline in the UK can be up to 5% ethanol without being labelled as such, and fuel blends are changing all the time depending on supply, seasonal variation etc so what's at your local garage one month probably won't be the next.

All that said, I'll do what I can to avoid ethanol fuels in my Morini for as long as possible. In the absence of knowing the exact fuel blend at each pump, that'll probably mean me sticking to premium brands and hoping for the best. Ultimately though it's coming and like the removal of lead from fuels a few decades ago, owners of older vehicles will have to see how their machines stand the test of time- some will be fine, some will have all manner of problems, some people will get rich from selling solutions and many will try to jump on the snake oil bandwagon.

Hi Tom;

That reply is worth putting in ATG...

Good riding, while we can

CC