Can someone advise if E5 super plus unleaded is OK in my 1976 Le Mans, or do I need to use a Lead replacement additive ? I would prefer not to use the E10 regular.
Thanks
For what it’s worth, I use E5 in my 78 sp1000 and 71 Norton commando 750,alm good to go.
I run my 1982 G5 and 1980 V50 on E5 Super without problems. When touring in Europe, where E5 isn’t always available, or in Southern Ireland, where it is unobtainable, I have survived short-term on E10 with minimal ill-effects, but have always refilled with E5 as soon as available. If you’re concerned about valve-seat recession then a lead replacement additive will help; these also contain stabilisers that should offer some protection against fuel degradation. My principal concern is the ethanol content rather than the absence of lead: one of the most pernicious properties of ethanol is that it absorbs moisture from the air and, as we all know, water has no place in an engine. It also tends to degrade older formulations of rubber, which may affect fuel lines, seals and o-rings in the fuel system. E10 fuel contains, as the name suggests, 10% ethanol; E5 contains “up to 5%” ethanol, but in fact many E5 fuels contain little to no ethanol. This means you can safely leave fuel in the bike without fear of attracting unwanted atmospheric moisture. I have always taken the view that “if it has carbs, use E5”, but of course there are exceptions and – as always – best do your own research.
If I would make one suggestion, it would be to not leave alcoholised petrol in any motorcycle for long periods e.g. over winter. I have had the dubious pleasure of dealing with the carnage caused by super unleaded languishing long term in an MVAgusta Brutale. Rusted out fuel pump, gummed up injectors rotten fuel lines , big expense and hassle.
So come winter time, drain off the E10/E5 and replace it with Aspen or Storage fuel.
Esso used to sell super unleaded in some parts of the country which didn’t have added alcohol. Apparently, this has ceased to be.
E10 is designed to be used by modern cars and turned over promptly. If I had to use this it would be because I could not get E5. On older classics E5 with a stabiliser makes some sense for regular use. However Project Farm on Youtube investigated this as to what happens over time and water absorbtion remains an issue.
I have used E5 ever since ethenol was introduced into petrol and have never needed any kind of additive! E10 was designed to be used with fuel injection systems with a higher pressure and finer vaporisation than carb systems so id say that for any carburetor bikes stick with E5 ( I also use it in my two-strokes).
I concur that when doing so unless the bike is in regular use(at least once a week!) IE- if stored over winter than drain the carbs (at least this is easy on guzzis) and the tank as well! to prevent water absorbed fuel getting into the engine.