Rattling sound when backing off the throttle on my Ryker & more - any advice?

[seger]

Hello! I have a rattling sound when I let off the gas on my Ryker! I have 2 and one for the wife, and hers is completely silent. It wants to chop sometimes when I drive away.
Is there supposed to be oil in the variator? That may have disappeared, because it sounds like it's dry, if you know what I mean? Can it be repaired or is it only a new unit/variator that applies because I don't think this will last over time? Can I take it apart and add any grease to the unit? Are special tools or pullers needed to take it apart? If anyone has an exploded view, it would be appreciated! It has traveled about 1000 km, here in Sweden there is a very poor service organization, and they are not that common either. Would be grateful for help with my future problem!