for the record, my snark now does betwee 37-40mph. it started out at about 5-9mph. so a great improvement. if you can, try a 52 jet on that.
also, check the muffler (the snark mufflers are beautiful, if you got the two-piece model). cleaning it may help you get more power. also, take the cylinder head off and check for carbon build up. also, try a new spark plug (i prefer a bosch 4214 platinum).