Aerox Engine Rattle?!!!

Hey peeps.

I noticed that on tick over you can hear a metal like rattle from the engine. On closer inspection I found that the metal plate at the very back behind the variator (the one that has the teeth on it) - sorry for being so technical! Lol, has slight movement and believe this to be causing the noise.

Does anyone have any ideas on what may need replacing? Have added a pic to show the part im on about.

I have been advised that it could be the 'Starter Clutch' that has now worn causing movement (Link of new one - http://www.adrenalin-pedstop.co.uk/p/Starter_clutch_for_Minarelli_engines_–_Nitro_Booster_etc-2601.aspx )

Has anyone replaced one of these and have advice on how to do it? Is it simply and unbolt job once you remove the variator?

Your help/ advice is very much appreciated.

Thanks

Will