1pc CNC motor mount for LSP??

[MX_KEVIN]

might as well take the backplate off and do the flop test with a hole in the side of the case like that.

most definitely it'll effect the compression.

How so? Theres already 2 big holes in the case, intake and exaust. Once the piston is past the ports there taken out of the picture and compression builds...Hole in the case or back plate off wont make a diffrence in a flop test. A loose seal between piston & sleeve will.
The real question is, is a flop test the real determining test of a good or bad engine. I dont think so, but if it flopped slower before the case break than after you can assume some wear happened there. Think positive. Maybe the motor just broke in and is now in the sweet spot.