Sounds to me like the pull start cord wasnt wound tight enough when you fitted it bud normally because the pistion is in the high positin, try refitting it with the pistion low, but dont fit it straight, when you put the pull start to the mounting plate put it so its about 45 degrees out to the right then turn anticlockwise to line up the screws holes that should help tighten it abit. But can just be a case of trial and error mate