It should have a "T" and an "F"......they're just hard to see sometimes. If you can't see them, remove the sparkplug and put a drinking straw down into the cylinder and let it sit on top of the piston. Now rotate the crankshaft until the drinking straw comes all the way to the top and stops, before starting to go back down. When the piston is exactly to the top of it's stroke, that is top dead center and it should be aligned with the "T" mark. That's what the "T" stands for.......top dead center. When you're satisfied the piston is all the way to the top of it's stroke, just look at the marks on the flywheel and the mark that's aligned on the flywheel should be the "T" mark.
Most 4-wheeler problems are caused by a loose nut connecting the handlebars and the seat!!
You only need two tools in life -- WD-40 and duct tape. If it doesn't move and should, use the WD-40. If it shouldn't move and does, use the duct tape.