JohnnyBeckett wrote:ethanol loves to eat rubber pipe alloy brass cork and metal
The problem with blanket statements like this is they aren't based on fact. Ethanol does attack rubber hoses that are not made specifically to resist ethanol, so that part of the statement may or may not be true depending on the specific rubber. However, the rest is incorrect.
Wine (~12%) and fortified wine (~20%) can be in contact with corks for decades (in a few cases, hundreds of years) without degrading the cork.
I've been running a long-term experiment on the effects of ethanol and gasoline/ethanol for about a decade (my notebook is in the garage with the starting date). This experiment ran in parallel with one on the effect of a name-brand gasoline stabilizer that ended when there was nothing but a tiny residue of the fuel left. I measured the evaporation rate of the fuel as well as the weight of the final tar-like residue. The most volatile components are needed for easy starting and those disappear quite quickly, and at the same rate with or without stabilizer. Anyway, without going into the details just now, my conclusion from that experiment is the stabilizer had no effect whatever. As a result, if I won't ride a bike for longer than a week I drain the carburetor because of the resin-like film that forms in the pilot jet as the fuel evaporates.
Anyway, the experiment that is still running has a piece of an Amal Monobloc carburetor and an Amal brass jet in "pure" ethanol/gasoline from the pump, that plus the recommended dose of stabilizer, that plus the heavy recommended dose (i.e. twice as much), and 100% ethanol. The containers have sealed lids to prevent evaporation and I have measured each piece with a calibrated and extremely sensitive laboratory balance periodically over time. After a decade there has been no
measurable loss in weight of any piece in any of the above mixtures, including pure ethanol. If I had my notebook in front of me I would quote percentages and error bars, but I'll just state my conclusion that ethanol has no
measurable effect on the alloy of Amal Monobloc carburetors or the brass of their jets.
To summarize, you do have to replace your rubber fuel lines with SAE30 R9 and drain your carburetor if it will sit for more than a week. Adding stabilizer probably doesn't do any harm, but neither does it do any good.