I obviously ran into an issue trying to "CC" the chamber from this end using colored water. Its really "skinny" where the squish band is and water has a "skin" on it (thats why water bugs don't sink),so its hard to get the water to flow into thin areas. I could have used colored alchohol and it would have worked fine. I could have also added borax to the water to soften it,but for times sake I just taped up the hole,flipped over the head and filled it from the other end until it reached the bottom spark plug threads.