thers two little marks on the cam tower, and two marks on the cam sprocket. usually they dont line up "dot to dot" make sure your at top dead center, and check! the right side line on the sprocket should down a little than the line on the cam tower. the left should be just the oppisite, the line on the cam will be a little higher than the line on the cam tower. and when you think you have it turn the motor over by hand to feel if anything hits. never pull start it if you dont know its in time or not. that could end with bad results! hope this helps and good luck!!!