I have a 2005 vino 50cc with only 500 kms on it. I cant get it to go over 40 kph. thats at full throttle and it bogs. I can let off the throttle about halfway before it starts slowing down. Compression is 120, new plug, fresh gas. Took it apart and had a mech look at the rings and head and pot and all is good. It also smokes more than it should. My sister-in-law has a 2007 50cc and it leaves me in the dust.