What worked for me with two stroke gas mix residue on my moped was the paintbrush cleaner sold by one of the local BORG's. I experimented with kero, acetone, paint thinner and a couple of other products, but got the most gunk out with the PB cleaner.
As far as the rust, Vinegar, Evaporust, and other products can eat that. Moped Army actually has a pretty good Wiki that details the options and gives the pro's and con's of each.
Paul