There is a kit to replace the rubber within the fuel pump system. 912is Rotax part number 889537.
I tried installing Silicone coolant hoses from Auto parts sources. It is difficult to source bent stuff unless it is in your hand. I ended up ordering
new Rotax Silicone hoses. I didn't like how the straight silicone hose resists a radius bend. It likes to collapse with minimal radius. All the hoses specifically on the
engine will be replaced with Rotax Formed Hose parts. The unfortunate thing is that the Rotax Silicone is ugly brown. Had I known that I would have sourced
brown for those segments that I do have installed to the cabin heat as well as the hoses directly attached to the main radiator. I have a fairly good segment of
silicone hose I can't use so Ive waisted money in the end. You can download the Rotax Parts Manual from the FlyRotax website. Good luck.