Howdy. So I just picked up a 2008 yz450f that was my brother in laws and it had about 50 hours on it and is box stock. He had done a full service on it before he sold it to me because it sat for a long time and so far it has been an extremely fun bike. But I have some concerns 1. The bike seems jetted lean. It seems to back fire a lot when I roll off the throttle. Does the stock needle have a clip I can adjust to try and make it a little more rich? 2. The bike leaks some oil out of the over flow when it gets hot. Not a lot but is this something I should be worried about? 3. I put about 50 miles on it so far of desert trails. Once when I was in 5th (not tapped just cruising) the bike died like it was running out of gas. Scared the hell out of me I thought I blew it up. But it restarted first kick and ran like a champ the whole way home? Could this be due to jetting? I recently added a desert tank if that matters. Thanks for any help!