So I upgraded my venerable Raptor 30 v1 to a Raptor 46 (approximately a six-pound helicopter with a five-foot rotor span). It has some issues with the engine when I tried to fly it recently at the field, so I took it home and fixed a few things here and there. It turns out I'd lost the two screws holding in the carburetor on my OS .46FX-H; I pillaged another set from my similar aircraft motor. I bought a brand-new high-performance muffler, got it attached, and started running it up and checking things out.