When the trans get to a the right RPM's, theres a small (im gonna say) "nob" the sticks out which then makes the 2nd gear lock into place with the first = shifted into 2nd gear. And u adjust the shift point with the 2nd screw thats a little more at an angle.

You really have two options when it comes to the fuel line, #1 get a racing fuel tank so u dont have to worry about it. #2 get longer fuel tubing and route it along the handle. I have the tubing on mine mounted on the handle and used zip ties to hold the filter still