[ppfpooghn]

I believe the sound you are hearing is the clutch plate (the clutch), ticking and clanking against the gearbox. I can't be too sure though and I don't think there is an easy way to check without taking the gearbox out. Having just replaced the master cylinder sounds like it could have something to do with the hydraulics though. Are you a member of the NRMA or know someone that is? I'd imagine those guys could tell you in no time.