RE: YS 110fz lacks of power
Check your regulator diaphragm. I had trouble with a 63 that would not get over 8,600 RPM. Idled well, etc. Changed the regulator diaphragm and it zipped right up to 10,500 ~ 11,000 RPM. Been a go'er ever since the change. Be careful not to lose the little parts when you open up the regulator.
Chip