So far, I thought Superplus was the longest-lasting type of petrol. Now my outboard engine didn’t start, which has been refuelled exclusively with Superplus since 2011. Carburettor opened and see here: Gammel everywhere and a kind of jelly in the float chamber. The engine was rarely used, about an hour per year (is a pure auxiliary motor and therefore has always completed only short operations). Over the summer it was attached to the boat, salt water was often nearby, but did not come into contact with the engine for long periods of time. Externally it looks like it was peeled out of the egg. Over the winter it hung in a dry garage. Since the manufacturer did not provide an easy way to release fuel from the carburettor, after use only the gas tap was closed and maintained until the engine went out of its own accord. How can I avoid it in the future by another type of petrol or certain additives or other handling?