My clutch has started to make funny noises. I've noticed it the last couple of times I went out. In neutral, if I let out the clutch, clunking noises come from the engine, it clunks faster if I rev the engine. It also makes clunking/chattering noises if I accelerate hard from a stop, eg. if I try to wheelie. It's an FZR600 engine. I've never ripped into the clutch before, what should I look for? Thanks for any tips.

BTW, checked the chain, its well oiled, no tight spots, proper tension, so I'm pretty sure its from inside the engine somewhere.