The Chain I have tried tightening and slackening off. Following someones advice on the forum that it should be loose enough to almost touch the swinging arm with a little pressure. The chain always seems too loose to me but I have never had a bike of this type before.
The cush drive seems to have about 1 to 2mm of slack. The bike has only done 3500 mls and seems to of been looked after. It is just over 2 years old although it is probably an 05 or 06 model.
The ECU ends in 00 but I cant see any paint on the rear. There is a large white label on the back which is a little faded but I think says
No Motore M806E816322
Cod Motore 5VK-E900100
There are a couple of small white circular stamps on the front of the ECU.
Hope this gives you a few clues.