Actually when the crank is 12:00 & the cam dimple is 12:00 it is at TDC firing #4, not #1 like most engines. Both 1 & 4 will be at TDC, but #1 is on the exhaust stroke in this position. It's also possible the cam cog may have a false keyway... if it has 2, you need to use the "E" slot, not the "I".