Reoeatubg myself:
ORIGINAL: ameyam
Running my 55 without cowl. Heat is not the issue. It loses compression when hot and after a few seconds regains it. We didnt run-in her properly last year, that could be the issue. I could rebuild with a new piston-liner but that would be expensive
Ameyam
I think you are just not used to ABC type glow engines.
When the cylinder gets hot, the engine may indeed feel like there is little to no compression as the piston will slide far more easily in the cylinder.
You should feel some pushback because of the trapped air in the cylinder head, but this is still considerably less than when the engine is cold.
FYI: I have one well worn .75 Tower engine that feels like it has absolutely NO compression even when cold, but that engine remains a STUMP PULLER.... a very powerful engine.
The 55AX is perfect for that plane, you should NOT be trying to fix one problem by introducing another.
Fix the fact that the engine cuts out.
You likely have plumbing or pressurization issues, or you are still running the engine too lean in spite of what you may think is the proper setting.
You'll need to find what is to blame and deal with that.