How can i improve performance on my kx 85 with spending any money?

Question

can i make my kx 85 any faster by doing anyting to the bike that wont cost a penny

Answer 1

flip your rear tire around.. the worn edges will be on the back now and the sharp k***s on the front where they can get a good bite...  the added traction will feel like a few horsepower to you-

Answer 2

Ask someone you know to look that is good with bikes and does their own work to look at the jetting as having it right can make a difference.  Make sure you clean your airfilter regularly.