Here are the weights of the FTL 45 Gas Engine sold by United Hobbies.

I believe my scale is pretty accurate ..... Measured with included Muffler and hardware.

Engine with Muffler, Carb and Spark Plug attached 3Lbs 6.8 Oz. ( 1555 g , 1.555 kg )

Engine as above minus Muffler and muffler bolts 3Lbs 0.4 Oz. ( 1375 g , 1.375 kg )

Muffler and Muffler blots ONLY 6.4 Oz. ( 180g )

Ignition Modlue with Spark LEAD and other wires 3.8 Oz ( 112g )

Ive not run this engine yet.

Just got mine weights on my digital scale are

engine: 48.2 bare no plug
muffler: 5.5 no hardware
hardware:2.8
Ing: 3.9

looks like our weights are pretty close

Piled everthing on the scale that was in the box except the plug wrench- engine/plug/muffler/hardware/4cell battery. no stand offs or switches and the weight was 65.1 oz

I see posts on other engines that are lighter but I don't know if they included everything to make the truely RTF everyone likes to cheat on the weights to make their engines look lighter
I have access to a Bril 46 I'll try to get all the goodies on the scale to compare with the ftl45