I just bought a used metro 50 wont start I don't know what else to do, I've cleaned the carburetor, reset the ecm, flushed fuel tank filled with new gas, adjusted the valves, have 150 lbs of compression, new 5666 ngk plug and wont start. Not sure what i'm missing it has a Yoshimura Stainless Steel Exhaust, aftermarket cdi box looks to be installed right could that be the culprit?

Any help or suggestions would be appreciated.

Thanks Brent.