Blaster Idle Problems

Well, I just repositioned the needle jet... it was up one slot from the middle. I moved it to the middle. Then I took it out for a test, and it's still bogging down and wont reach high rpms. It is fine when you sit there and rev the engine in neutral... then once it goes into gear it gets bogged out. I saw the transmission fluid leaking, and stood the quad straight up and down, and looked where it was coming from. It seems to be coming from directly behind the front sprocket somewhere. Where would this leak be, and how can I fix it. Would this be the cause of the bogging, or is there something else going on??