my xmas present this year was an aerox50 07 model,i have removed the washer from the variator and cut off the strange useless pipe that sticks out at the front of the exhaust removed the flap inside that half blocks the flow and welded over the hole..the bike accelerates much quicker and goes much faster, but after a few miles the exhaust becomes extremley hot to the point it glows red inside.. does anyone know if i have to change the main jet and go bigger? or is there something else i´ve missed..i dont want to buy a power pipe as they attract too much attention.