My boy had a 2012 250 with the delorto rear tank model. IT had less than 10 hours on the bike from a novice rider. Like new. It was a dog , I had a kiehin so ordered a manifold for thw bgger carb. The vacuum i take was a joke. It just would no pull any fuel. That 2012 the frame was like spagehtti. The head stay from frame to engine, we would lose that bolt no matter what, I finally double nutted it and red loctite. Any how that vacuum system is someting to run from. I could go on but this post would be deleted.