ZS190 Preventative Maintenance 

This video is about performing some prework on the ZS190 motor on my VMC GP-12.
TL;DW:
lots of info out there about these motors having starter chain issues, tight valves from the factory and decompressor not springing back on the cam.
lube the starter chain (usually come dry)
check valve clearances (mine was tight)
check if the decompressor snaps closed on the cam gear (mine did not)
searching on youtube, there appears to be some fixes for this, some say can add tension the spring more by wrapping it another loop around the mount its on for more
fyi: ooracing in the uk talks a bit about this and actually sells stronger material for the spring.
Next step, oil, first start snd running in the motor.