Joe, unless you add in a vibrationmount, the BME 55 has the mounting lugs cast into the back of the crankcase, so all you do is bolt it to the firewall in the same fashion as a twin.

Weight for the 55, bare, is just under 2 lbs (Including plug and prop nut pieces), so add in 3 ounces for the ignition, 5 for the muffler and then whatever the prop , battery, and spinner add to that.

2.5 lbs ready to run, add in 6 ounces for a battery and switch harness and you are still under 3 lbs.

Compare this to the Brison 52cc engine that just came out, that weighs 48 ounces BARE, and the BME is a solid pound lighter (similarly equipped), and is also about a pound lighter than the DA 50, Taurus 52, or any other "50cc" class engine.