well theres a slide adjust screw on the left hand side it points up wards you can use that to adjust the throttle on the carb-the lower one is the air screw
what does the plug look like?-you need a tan color
try klotz oil it is verry good oil ,great for powervalves,-it helps remove carbon build up,and burns clean
clean the air filter
try the 60 pilot again,mix the oil -40:1 ,and check the plug
make sure all the vent tubes are clear
does it run erratic at wide open? you might have a stater side crank seal going bad
kick it -just after top dead center,thats what i have to do with my cr500,-a full kick