Rod1 - Shell VSX4 is the oil we use. It's what Skydrive recommended
100LL - I think you;re right. I've spoken to a Rotax service agent, and he also thinks it's the pressure relief valve. He's suggested putting a shim in to tighten it !?
Paris Dakar - You're are correct also, the Rotax service agant suggested 1 BAR as a minimum, but other documentation suggests 1.5 BAR. My Rotax manual says 2 BAR though, which is the limit I'll work to.
Thanks all for your help. Really useful info as always
