I understand the sea tankers don’t carry alcoholed fuel, and the Inverness Depot doesn’t add it. Slocal suppliers have alcohol free EN228, some have alcohol in it. We test after using sources we expect to be alcohol free.
The main enemy in MOGAS is ethanol and it is in most fuel sold in the UK, the only MOGAS sold in the UK without ethanol is the top grade of fuel from Esso.
Most of the motorcycle fraternity use this just before the bikes go away for the winter as it prevents most of the usual problems with MOGAS storage.
Peter wrote:
eaten the entire level gauge assembly
It’s not a Wolf 3500 by any chance? Ours did exactly the same thing. The dissolved fuel gauge plastic meant I recently had to get the carburettor, fuel line and fuel tap replaced in turn before it ran happily again.
Researching this problem at the time, thinking it was the result of old fuel, I found a friend had done consultancy work for a lawnmower repair specialist. A lot of their work is in spring when people try to start their mowers after the winter, and find they can’t. All they do is clean the fuel system, put in fresh petrol, and voilà.
The business owner uses Briggs and Stratton Fuel Fit Stabiliser (Amazon) in his personal mower, which should extend the shelf life from 3-6 months to 3 years. When asked why he doesn’t recommend it to his customers he said, “I’d have to fire at least a third of my mechanics, and I wouldn’t have a business after a couple of winters”. 
I got some this year, and will see what happens to the mowers and generator next spring. No idea how compatible it is with aviation.
Posts moved to existing thread.
I have a 3.5kW generator here on which the “car petrol” has eaten the entire level gauge assembly It did take a few years though.
As above, I’d drain it out.
There’s a reasonable chance it has got ethanol in it. I’ve noticed on the chainsaws and some garden equipment that can sit for a while that the fuel seems to go off much quicker than it used to.
Four year old Avgas, no problem. Four year old Mogas I wouldn’t use in anything including a lawn mower.
I flew the Jodel rear tank to empty, and the fuel drain was worked on. The engineer put in 10 litres to check the seal. The can he took it from had been sitting unused since December 2016, following the sudden death of its owner. He didn’t know this.
My options are to drain, (slow and difficult) or fill up with 45 litres avgas, and switch to it at a safe height. Front tank is always used for t/off.
Risk of sticking carb bits??
How do you transport the fuel to the aircraft?
I fly a C172P for years and allways kept in the back side of my brain that something could happen anytime about AvGas.So I obtained an EASA/FAA STC for Mogas .This is a simple documentation for this model ,without any modifications.Kept using Mogas UL100 sporadicaly. LGKO Intl where I'm located, tried the hardest for years to expell the GA from its grounds,first requiring PPR and then responding that its gigantic west apron is full for GA. Eventualy the AvGas operator couldnt survive like this and removed his station 1 year ago ! I dont see any GA in the apron any more and everyone seems happy.Bureaucrats cannot realise what missing revenues from "non all inclusive low cost tourists" harm the island.Such as Taxis,Car Rentals,Hotels,Restaurants,Souvenirs,AvGas VAT,Airport Tax etc.Seems a rocket science to them.They still feel secure and immovable,allthough the general population suffers the most for the 4th year. So,I totaly converted to Mogas 100 with great success.Same performance,lower temperatures,same mileage,50% cheaper than Avgas.2Years,150 hours without any trouble even at 10000 feet.Just stick to the same provider and make random color ,water,and alcohol tests for which I never found anything wrong. Oh..BTW,the PPR NOTAM doesnt exist this year but the dammage has been done./
Mogas is a problem in infrequently used vehicles - it does tend to "go bad". Avgas keeps much better. Things like motorboats that aren't used daily often end up with varnish in fuel tanks, fittings, carburettors etc. which can result in bad running and engine stoppages. (My dad bought an old boat that had sat for some years, and we had to do a lot of work, including removing the fuel tank, to get all the solid fuel residues that were blocking the fuel filter).
