I got a 2005 Yz250f. I changed the head gasket a while back because it was burning water and im having a bitch of a time getting the bike operational again. At first i had the timing totally wrong, then i fixed it. The bike still wouldnt start. I then realized my piston was at BDC when i timed it so i re did the timing again, Checking that the piston was at TDC with a wire down my cylinder. Now the bike stilll wont start, just sits there and backfires if i have the choke on. I watched a youtube video and it showes the guy using the punch mark or "eye" on the flywheel and lining it up with the marks on the stator cover to set the timing, and on another video they used the H to set the timing. Any ideas?