Benelli Andretti X50, are all of them 70cc stock?

[tate]

So the other day I picked up this here Benelli Andretti x50. Its the top of the line QJ 2 stroke minarelli clone. Its actually at least as nice as a Yamaha Zuma (the old 2 stroke ones, not the new castrated 4 stroke ones) if not nicer.

Anyway I pulled the top end to check it out and immediately noticed a few things.

1. The head is not your standard QJ head. It has an O ring and seems to be a higher compression head.

2. The bore/piston are something like 46mm. Certainly bigger than the standard 40mm.

Are all of the Benelli QJs like this? I have heard people saying how fast they are and this would certainly explain it.

The stamp on the engine case is the standard qj1pe40qmb or whatever but that wouldn't stop someone from slapping a much bigger cylinder on at the factory.

I figured someone along the line must have thrown a kit on this engine but then I saw this on ebay.

http://www.ebay.com/itm/50cc-Benelli...9706f9&vxp=mtr

its identical to my top end and obviously bigger than the standard 40mm bore. Note the fact that there is no displacement listed on the cylinder. Generally it will say something like "40MM 49CC" or some such thing. That one is completely blank just like mine.

Anyone out there own a Benelli scooter and able to confirm that all of these bad boys were kitted from the factory?