(First published in ‘Focus’, the newsletter for Cornwall A7 Club)

From first hand experience….

Most of us have read or heard about the problems caused by Ethanol fuel and now add additives to our fuel
to compensate for the problems. I have done this, but have any of you physically seen what Ethanol actually
does to our car components?
I have now encountered two situations, which I can only say have been caused by this fuel.
1. Some two years ago now, the engine on my 12/4 seized. I will not fully recount the problem or how I
solved it – better done over a pint or two – but briefly, I had to remove the cylinder head as No. 4 piston had
seized with No. 7 and No. 8 valves. The exhaust valve being open to the atmosphere via the exhaust , the
whole of the piston and valve area was covered by a white mould which was growing on the valves and
down the valve stems.
2. I have just purchased a Big 7 and even when I test drove the car it was Kangarooing. I assumed some
form of fuel starvation, but the car drove well, so fuel, no problem. The elderly gentleman who sold me the
car said this happened now and again. I trailered the car home from the Manchester area and started to
solve the fuel problem. On taking the banjo bolt out of the carburettor fuel intake, there is a gauze filter. This
had small specks of a black substance, which when rubbed between my fingers was almost like a paste. I
also then cleaned then carburettor bowl – very mucky and black. I assembled it all, two gallons of new fuel,
started car and it drove well for a few days. Then the same problem appeared again. So working back from
the carburettor down to the fuel pump, removed dome cover, checked washer – all okay. The circular gauze
filter had black specks, so cleaned and placed on one side. Black diaphragm removed by pushing down on
the spring and twisting, so disengaging the connection, this now exposes another bowl, and this was covered
in a black substance which I removed with a small artist paint brush and petrol. So where has this black
substance come from? I checked the black diaphragm and found it disintegrating on its edges and when
rubbing between fingers it came off like a black paint.
I purchased an Ethanol Resistant Diaphragm (RED) from the Austin 7 Workshop, cleaned and checked the
small inlet and outlet valves in the pump. Re-assembled all. And have now done some 150 miles and touch
wood no problems.
So it may pay you to check the colour of your diaphragm, because this fuel will not go away. There has
again been some talk of increasing the ethanol content to 10%.