RE: O/T Petrol going bad13 May 2020 09:44
Three years ago I parked my carbureted motorbike for the winter fueled with E5. In the spring it appeared the four carburetors were completely full of gum. The motorshop dismantled it and cleaned them ultrasonically. Nobody told me it was perhaps because of the E5 petrol.
Last year problems started again. I went back to the garage and they told me that all combustion engines that sit unused over the winter period have these kind of problems (especially motorbikes, gensets and garden equipment).
Remedy: Do not use E5 or even worse E10 petrol. I then used a Forté fuel cleaner and it became a little better. However garage told me I probably had to let them clean the carburetors again (€500,-) to really solve the problem.
As the problem only occurs below 4,000 rpm and starting is no problem I let it be and do not use E5/E10 anymore. I use "BP Ultimate", "Shell V Power" or "Esso Synergy Supreme+" as these fuels do not contain ethanol. Completely solved the after winter start-up problems.