Pictures, there is carbon build up on piston and in combustion chamber.
Yet, the cylinder wall feels smooth, no scorching, etc.
Is it possible some carbon is keeping the valves from seating 100% and that's why not 130psi?
I'm thinking this:
I'll clean the carbon off the piston and the combustion chamber, press the valves and clean with wire brush the valve seat.
Do a simple re-assemble and see if compression comes back up.
If not, then next step is piston removal and compression ring check/replacement right?
btw, I have never took the engine apart, no gasket at all.
Typically gasket between head and block I'm used to, these GY6 none?
