i thought i knew a bit about motors but this one has got me foxed,it is non-rc with a black plastic venturi,takes standard size plugs,the muffler is an aluminium ring sandwiched between lower cooling fin and case a la cox,the muffler has 1 hole about 3mm for the gases to exit,it is marked as a 15 but doesn't look that big and the case has what looks like a 'j' cast into it,the case backplate screws into the case,it has beam mounts as well,help.