sboxer : don't make this into a harder problem than it is, most magneto sparked engines require a minimum number of rpm's before they will produce a spark; with your sparkplug removed there is no compression for your drill to overcome, with it installed your rpm's drop, probably no spark, as ryobi engines require 300-400 rpm cranking speed before spark is produced. That being said, be sure your fuel line is on the correct inlet tube,one tube is for priming and other is fuel inlet. Tube w/90 degree bend is fuel inlet,straight tube must be blocked off if not using primer bulb good luck cal .45 acp