There are a bunch of threads about compression, a simple search should turn up more than you really want to read.
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"I would rather be exposed to the inconveniences attending too much liberty than to those attending too small a degree of it." - Thomas Jefferson
you could try removing your lower gasket on the jug and use rtv sealant. Just make sure that your piston can move all the way through with out hitting the top if it does you can make a simple cardboard gasket with rtv sealant on both sides of it to give you a little xtra room. I'm running my motor without the gasket and it helps a little bit with compression but I also had to trim the piston skirt (but i did that anway)