I had a few hours to spare this afternoon so I drained the gear oil out of the Sisis. It wasn't too bad in colour or texture unlike the engine oil which I drained a few days previously. I refilled with fresh SAE30 oil to the required level. I used some of the old gear oil to give the metal work a quick wipe. I also gave the chain a quick spray of chain oil at the same time. Overall I am very pleased with it and it now runs like a sewing machine.