Petrol tanks and ethanol.. - Vintage and classic motorcycle

Personally my aggravation with ethanol has been minor. I haven't noticed a great deal of difference in running, nothing that a tweak of the carb settings won't cure. What I have noticed are minor foibles, prematurely dying spark plugs on machines that have been left standing. A carb 'varnished' on the insides from slowly dissolving pre-ethanol Petseal tank liner to the point it stuck wide open. A greater than expected number of 'weeping' fuel taps. My main beef with ethanol has been the outlandish pointlessness of it. Burning it is no better than burning hydrocarbons and growing it takes land away from food crops in a time of rapidly growing population and climate catastrophes with the backdrop of regional conflict brought on by poor harvests. Our Governments actually subsidise and promote this cul de sac of idiocy whilst the market itself is inextricably moving towards electric vehicles.

Of late though I have found one more reason to hate ethanol, in the last year three of my machines have been stricken by tiny pinhole leaks in petrol tanks. The racing Bantam sprayed a fine mist of fuel over my crotch from a leak in the top seam as I thrashed it through the Picos mountains during the 5000 Curves. My J2 Enfield sploshed toxic fuel down my leg as I set off for a gentle Sunday run a couple of months back and the Gilera dripped and dripped over a hot engine threatening spontaneous combustion in a Social Club car park.

These leaks have all been from the top seams of tanks. It is commonly held that ethanol can secretly rot out the bottom of tanks as it degrades and forms a layer of water and promotes an electrolytic reaction. I have found that it seeks out the tiniest of weaknesses and exposes them.

A little research reveals that ethanol has a slightly lower viscosity than mineral based fuel, could it be that small holes overlooked by good old fashioned pre-ethanol fuel are highlighted by the accursed plant juice?

Whatever the case it is here to stay and I have three petrol tanks with holes that need to be plugged. A review of at least one petrol tank sealant brand will be forthcoming.....