Hey Guys I have a HERO HONDA KARIZMA December 2006 model. I have lots of problem related to my bike. the big issue is the mileage of bike. my bike's mileage is 15-20 km/litre and my other friends 2004-05 model's giving 30+ mileage. SO what will be the problem for that low mileage and how can I improve my bike's mileage?