I am a 220 pound rider. Must of the time off road. But recently i am riding in a MX track near home, and really like it. My bike is a RMX 250. There are some tables that i see other riders jump so easily, and i just get to the middle of the jump. I go with gas full open, and nothing. What can i be doing wrong ? Am i and my bike too heavy for this kind of riding?. How can i improve this ? Thanks for your help.