My Step-dad has told me that swapping out the engine will work, because my bike essentially is the frame of a 125cc bike, but for some reason, with a 50cc in it. looking at the bike this really is apparent, Due to a massive gaping hole between the top of the engine and the bottom of the fuel tank. ôÿ "ªŠ?„ˆªÚ +"9ií! ‘²pþþ"0nâc çû -õûb2‰®áoS²k j!‹E‘~ÚØÖkùé}KnO·¤Ã n !¡€jEŠ–yN Ù,Ë Ä“Å $3—ªeÕ®C–õˆDÙùÞs So short of buying a separate 50cc frame and 125 motor and combining them or chopping two bikes up (defeating the point of trying to save money), you can't ride or insure a 125 as a 50. A restrictor won't change anything, it may be as slow as a 50 but in the eyes of the law it's still a 125 and still illegal for you to ride. Suffice to say that if the engine or motor is bigger, the scooter or the moped can achieve faster speeds too. So, in essence, 100cc, 125cc, and 150cc scooters have higher top speeds than a 50cc scooter. A 50cc scooter typically has a top speed of 30 mph, and a 50cc moped has more or less the same speed. A 100cc scooter can reach about 60 mph. Ok i just put a polini 70cc kit on my 50cc vespa. is it possible to get a bigger engine again. ie a 125kit, replacing the crank, conrod, and driveline gear with aftermarket stuff? My fly is a 2006 model and the engine is about 2008 Vespa lx 125. The leader plug's 5 pins are the 3 phase, one pin is the oil sender, the last pin is the pickup, you will need a 3 phase leader regulator £16·00 pedparts, this has five connections 3 phase wires in, the two out are a stable + & - @ 12v connect to the battery (charging your Would i be able to fit a dt 125 r engine into my dt 50 r frame. I would buy a 125, but i would prefer the fun and satisfaction of this (i pressume) complicated swap. I basically just need to know it fits before i go out and purchase my self a new engine. But I read thet this is costly (it can cost even 1000 PLN) and you can drive only mopeds to 50 cc with it. In case of license A1 - you need to have 16 years and you can drive motorbikes to 125 cc with it. In case of licenses A2 and A you need to have 18 years. A2 is for bikes with power lower than 35 kW, license A is for all bikes. x5A4.