Hi, it sounds like the hydrolock is caused by too much fuel getting into cylinder, not a good thing. I guess you were able to take glow plug out and blow out excessive fuel by turning over engine with electric starter. I had a TT 46 inverted that would lock up on me if I just marginally over primed it. So, my suggestion is, don,t over prime, make sure fuel tank is not too high relative to carb. , good glow plug. Good luck.