Modern gasoline breaks more than you want!

Ton - the owner of Vincents Motorhuis - was gradually getting a headache. Another young timer with fuel problems; again one or more leaking carbs; weather leaking rubber gaskets; float needles again that leaked on the deposit; another customer who drove off with a well-running young timer and called two days later with the announcement that the engine no longer wants to start or was leaking from one or more carbs, to make you crazy.

Inquiring with colleague motorcycle shops whether she recognized these problems resulted in hours of discussion material. Ton was not the only one struggling with this. What was striking was that only carburetor engines suffered from this, and in particular those from years around 1990 and before.

There were even questions from other motorcycle shops whether they could not send their customers with older motorcycles to Vincent's Motorhuis. After all, Ton has an almost inexhaustible stock of carburettors from mainly older Japanese motorcycles. But Ton already knew that his large stock of old carburettors would not provide any light in this dark matter. He had already discovered that replacing all rubber seals was only a temporary solution. In no time the whole thing was leaking again or the engine was “drowning”.

It is so bad that he has almost run out of float pins and rubber seals without this having resulted in a definitive solution and thus a satisfied customer again. Increasingly convinced that the problem had to be in the fuel, Ton started to identify which fuel his customers were using in the hope that he could pinpoint a culprit. The only thing that emerged was that no particular brand of fuel could be identified and that almost all customers refueled Euro 95. Then it was time to investigate whether - and what - changes have been made to modern fuel, particularly Euro 95. This yielded the following information.

European legislation requires that a percentage of alcohol - chemical name is ethanol - is added to fuel for combustion engines. The idea behind this legal regulation is to reduce the use of fossil fuels extracted from petroleum. Based on this legal regulation, it is prescribed that every liter of Euro 95 to 5% bioethanol is added. This is the situation at the time of 2012. In the longer term, the ethanol additions will go up to 10% (already for sale in Germany and France) and in the distant future possibly even to 20% ethanol.

The fuel manufacturers have of course conducted research into the effects of adding ethanol to the fuel. Only ... you do research on contemporary combustion engines, you discuss results with the car and motorcycle industry, as well as any adjustments for the future. It is a joint venture with joint interests for the future. Is a light already starting to light up? Classics and young timers do not participate in this study!

In terms of combustion, there was a small problem with the addition of 5% Ethanol. Ethanol has a lower combustion value than gasoline. At Euro 95, this could still be compensated by carrying out the composition of gasoline with slightly heavier hydrocarbons, which slightly increases the combustion value. From a combustion point of view, it is therefore no problem to add 5% ethanol to gasoline.
Please note…. combustion technology.

The dissolving power of Ethanol is all too well known. Most of our young timers have "normal" old-fashioned rubber and plastic seals that swell or dissolve in ethanol.

Ethanol affects old rubber gaskets, hoses, seals and plastics. Alloys are also sensitive to ethanol. Even single layer fuel tanks (motorcycles) can leak. Have you noticed that more and more plastic tanks - ethanol resistant - are coming onto the market? Ethanol is also a good cause of problems with regard to water in the fuel. Furthermore, zinc, aluminum and magnesium alloys cannot always tolerate ethanol and that can therefore also be disastrous for the carburettor.

For hours I searched the internet for information and experiences about this problem which, I expect, will only get bigger because it is included in European legislation that in the long term (?) There will be a switch to 10% and even a still higher proportion of admixture.

E10 (fuel with 10% ethanol addition)
Approximately 90% of all petrol engines in Western Europe are suitable for E10 according to the German Environmental Agency (Umweltbundesamt). New vehicles - those from year 2005 - are generally suitable for E10. Most importers can provide information about the suitability of their models for the use of E10.

For our young timers with carburettor engines the addition of 10% ethanol is harmful! The best advice I can give is Don't fill up! Even one refueling can be enough to cause problems (see below the article of the ADAC).

If fuel with 5% ethanol, among other things, already resolves our old rubber and plastic seals, it is expected that this problem will only worsen when using E 10. But also when it comes to combustion, when using E 10 in young timers and or carburetor engines, an additional problem arises. The fuel properties are in fact considerably affected by 10% ethanol admixture, because ethanol has a lower combustion value than gasoline.

This means that more ethanol is needed to achieve maximum combustion with a certain amount of intake air. So one actually needs a larger nozzle for carb engines or ... more fuel needs to be injected. Was this problem with 5% admixture of ethanol still to be solved by slightly heavier hydrocarbons, when 10% is admixed, that trick is no longer possible.

E 10 therefore actually needs a different fuel-air mixing ratio than the old trusted gasoline.

Most motorcycle manufacturers release the use of E10 for motorcycles that are equipped with a programmed electronic fuel injection system with a lambda control. The following happens here. The lambda signals in the exhaust gases that not enough gas has been burned, so there is still oxygen left. The engine management compensates for that. Nice that computer-controlled fuel injection systems but .... there you go with your carburetor engine.

With newer engines (from 2005) there is therefore (almost) no problem. These engines have materials that are resistant to ethanol and almost all have a fuel injection system.

Thanks to Vincent. Or Ton ....
Zoeterwoude is the place to be.

And Dirk who sent the story