RE: YS 160 runs too hot in Genesis
I'm not sure if multiple slots work as well as a single BIG hole.
Try a 16.5X12 for break in and 30% instead.
Make sure you arent running it on the ground at WOT for more than a few seconds at a time. If the engine does not respond to HS needle changes (richer) while at WOT something may be wrong with the pump...maybe just the setting.
Colin.