My Novarossi's, Axe Rossi's and OS Speed's all still had metal lock up at 1 gallon mark. The Axe Rossi has the most lock up still and still jams on the starter box when its cold out. I would check the sleeve fitment to the case. If the sleeve slides out really easy, that could be one thing. I find that most engines that have a tight sleeve to case hold the metal pinch for the longest time.