I just lost the muffler off my new 50 cc RCG. Does anyone have a tip on how to keep a muffler from falling off. I was thinking of something like installing a short cable on it so it doesn't fall into the corn field never to be seen again.

I too had muffler issues until discovered the cure here on a forum. Here is the solution that works for me.

I do not use a gasket. I clean up both mating surfaces well and then clean them a final time with acetone. I then apply a very thin layer of Permatex Ultra Copper Sealer. I also put a dab on the threads of the bolts that attach the muffler (acts like a thread locker). Gently assemble the muffler to the engine and finger tighten the bolts evenly. I then torque it down tightly and let it sit for a day.

For me there is no more loose muffler and no leaks.

That and Nord Lock lock washers

I used the Permatex as suggested and so far it is holding. I had never heard of Ultra Copper.

Terrific stuff. McMaster Carr sells it for around 7$ a tube. It is high temperature silicone sealant with a twist... It resists gasoline exhaust great. I used NordLock washers several years ago along with the PUC, but have since moved away from NordLocks favoring PUC alone.... NL not needed. Try it...