leaking fuel cap??

Took my 2009 te 250 for her first ride today. Shes preaty nice espicialy jumping! handels so nice in the air anyway when ever I lean her over in berms and stuff fuel comes out the top like nothing probly lost about 3 ltrs out the top. So I went back to the shed and took the thing that makes like a lump on the tank off and it seald up fine. What is that raiser thing for? Also did any of you guys have trouble switching from a 2 stroke to a fourstroke? Its realyyy weird got any tips to get use to it.

cheers
sid

Yeah, I think that is a common problem/trait. My 09 TE 450 will leak like a sieve if I lay it over into a corner with a full tank. I tried another fuel cap but that didn't help. Tried greasing the gap/thread as well but to no avail. Im going to make up a rubber seal/gasket that will go under the fuel cap. Im presuming the riser is for a nice transition onto the fuel tank when riding up far forward.

Take the plastic riser piece off (left nut buster), make sure the rubber inside the cap is seated, not caught on one of the 'threads' in the cap, should seal just fine then. A little silicone spray on the tank threads will help prevent cross threading by making it easier to turn the cap, just don't get any into the fuel tank.

+1
I got to the point where I would inspect that the gasket was flush- not caught on a thread inside the cap- every single time I put the cap back on. Then I would tip the bike to the side and bounce the bike to ensure its sealed good- if gas came out I'd start over, if not I'd Pop-a-Wheelie

cheers everybody takeing her to her first race meeting today XD