A 22-8 prop is too small, you will get better results from a 22-10 Zinger or 22-12 Menz Ultra
Open both needles 2 turns from closed.
Start engine, run up to full throttle, adjust for best rpm, somewhere around 6800 to 7000(depends upon muffler),back off a few hundred rpm.close throttle to idle, around 1800 rpm..Open throttle--if it doesn't die close the low speed needle about 1/4 turn, try again..Do this until it dies when the throttle is opened, then open until you get a good transition..go back and re check the high needle..Fly......the factory needle settings are not always absolute..There are variables(high altitude, prop size, fuel, etc..Whatever works best is the correct setting.....
93 octane fuel won't run any better than 87..
Check all your fittings for air leaks, foaming should not be an issue...