Hi i just recently brought a yamaha aerox 50 2000 model the bike has been in storage for 7-8 years and i have only just taken the restrictor out of the exhaust. after doing this i put the bike back together and took it for a test ride up and down the road. The bike was running fine but after the engine got warm, the was a large amount of grey smoke coming out of the exhaust whenever i ride it however it does not happen when the bike is cold so could anybody help me to find out what the problem is please cheers. Ray