Boy I feel like an idiot. Doing a top end/ timing chain replacement on my 04 yz450f. Dissassembled and ordered parts. I've had this bike close to a year and its my first dirt bike I've had since I was a kid some I'm learning. Not new to engines however. I've figured out this was set up as a woods bike and just figured out this morning when I started reassembly that it has a trail tech 30 flywheel installed. Couldn't find timing marks so I looked up trailtechs website and read the installation manual which clearly says "the flywheel has NO timing marks use the oem for reference. I don't have an oem. Now what? Keyway line up maybe? note: I did read the cam change sticky but I guess my true question would be how to verify without the flywheel marks or is the keyway accurate enough(relative to whos eyeballing) Edited May 12, 2013 by Will.A.R.