Hier nochmal das Schreiben von Piaggio:
Dear Mr. xxxxx,
Following to your message received on the 06 of May, and concerning your question, we inform you that the Vespa PK 50 XL with frame V5X3T * xxxxxxx * was manufactured in 1988 with his original engine marhed V5X1M.
We inform you that Piaggio do not authorize any changement (substitution/conversion) - of the original engine from your P 80 X with the engine with 125cc fitted on the other Vespa PK125XL models. -
The Vespa PK 50 XL it’s not homologated, for to equipped the 125cc engine.
Best regards
On-Line Piaggio's Customers Service