I disagree completely, but am willing to drop the subject, it is not that interesting to me.
Most 2-wheel vehicle manufacturers declare correct (or slightly rounded) values.
For some reason, Kymco, SYM and some other like to present their 150 cc scoots as 200 and have been doing so for a long time.
Until 2-3 years ago, Italians DID NOT declare those models wrongly but instead, they were declared as 125, 150, 180, 200 cc. This is something Kymco never did. Hondas had 100 declared 100 cc models, so did Peugeot etc.
Obviously, in order to prevent Kymco selling more of its 150 units as 200 (Italian 200s - Beverly, Aprilia - are REAL 200!) due to fraudulent declaration, they started lying too. That`s the nature of the game.
Try to find ANY wrong declaration of displacement on Italian scoots prior to 2007-8 (other than rounding - 193 being rounded as 200; 493 being rounded as 500 etc.) You will not find any.