- Thu Nov 04, 2021 3:13 pm
#98830
I know you don't want to but you should drain the tank and carb.
Pure ethanol is hydroscopic, it will tend to absorb water until it is about 70% alcohol where it becomes stable. Pure alcohol mixes somewhat well with petrol. 70% ethanol less so.
So for a 15 litre tank, you have 1.5 litres of pure ethanol, that will absorb half a litre of water which if left to sit, will settle out in the bottom of the tank and float bowl.
Your choices are drain it now or drain it and strip the carb in the spring.
You could fill it with super unleaded before storage which is still only up to E5 which would be half as problematic but in reality is less likely to split and has a higher octane fuel fraction too (they blend crappier petrol in the E10 mix to achieve the same octane rating because ethanol is very high octane).
So, if you're not draining it, I'd suggest fill it to the brim with stabilised super unleaded. I'm using Frosts Ethomix in my old Jap bike because it has unobtainium pre-shaped fuel lines which are not even rated for E5.