Re: Spark Plug?
If it's a Skyhawk, any Skyhawk, then a NGK BPR7HIX Iridium plug, it's a difference you can actually feel. If it's a cheaper motor it may be too long so beware and crank by hand to check.
Note the 7 is a heat index number, they range from 5-8, the higher the number the more heat it will dissipate. Here in the desert in summer 7's and 8's are best, in cold places 6's may be be better, they hold heat in better and you'd only want a 5 if you lived in the artic.