I have just bought an old YZ 495 from a friend for £100 !! I thought it would be a nice project to play around with . It was built in 1984 , but the rear suspension is really rubbish. It has an Ohlins mono-shock system with a cylinder that is attached via a rubber pipe/hose. How do i either refill this or set this up ?. I think there is no oil inside it or has it got to be gas or something ? Any sound advice would be greatly appreciated. The rest of the bike is fine apart from the suspension. Thanks in advance ....