@hidalgo
well ravi piaggio 125, suzuki GS150 and suzuki GN250 have the exact same body frames. suzuki gn250's frame was used to make a similar bike with slightly smaller engine,i.e,suzuki gs150
ravi piaggio's designers took the exact same specs from gs 150 to design their bike (or maybe it was just coincidence that they came up with the exact same measurements :P), only added a sporty tank and side covers
keeping this history of developmnt of ravi piaggio in focus, i m pretty confident that suzuki gn 250's engine should easily fit a piaggio