I purchased a new Briggs & Stratton engine 2 weeks and replaced the old one on my Snapper deck. For two uses, it has worked fine. However, yesterday I replaced the blade and the blade adapter, and now the engine will not crank. The tension on the pull feels normal, and there's plenty of gas and oil. I didn't prime it more than 4 times. It sounds like it's so close, but it's just not firing. The spark plug looks fine, and I even tried it again this morning, thinking it may have been flooded. Any ideas that might help get this beauty working?