Base spacer and si 24/24 advise

Hi all

Im a newbie and poor in math calculation..I need your advise on my setup as i already install a pinasco px 200 60mm crankshaft with cut wall till flat on clutch side on my px150 crankcase. When i install the pinasco177 3 port alloy cylinder the top piston ring came off from the cylinder. I remove the cylinder out and install a 1.5mm base spacer and install back the cylinder but the piston also came off again. I need your advise on my si 24/24 carb as previously i had install a idle jet 55/160. Main jet 135, BE3 and air jet 160.Please advise on what thickness of base spacer should i use and correct jetting  should i use on my px 150 longstroke setup with px200 crankshaft. Please advise me in details..

Thank you.