150cc gy6 won't start

[scootie101]

ok well I have fuel and spark but compression is worrying me, it has compression but I don't think it's enough my valves are good just used grinding paste to seat them right.I'm almost 100 percent sure it's the rings but I don't know why they're leaking air they're brand new, could I have installed them incorrectly,maybe someone knows the right way to install the rings.