Small Engines (Lawn Mowers, etc.): Lawn Tractors Muffler is coming off

Question
I have a B&S Engine on a Lawn Tractor and recently, I was getting too much trepidation (vibrations from the engine block); I discovered that the four mounting bolts at the end of the engine tied to the chassis, were loose. In the process, the muffler unscrewed itself from the engine block, I guess because of the vibrations!.
Is there a material which I can wrap around the muffler (where it's machined) in order to force-screw it into the engine block so it won't unscrew itself again, especially when the vibration problem has been solved?!.
If there's isn't a material, what about some solution which becomes solid (as cement or stronger) at high temperature?.
Please, recommend such material and/or solution for such task.
Thank you,
Michael.

Answer
Vibration, like you described, will cause other nuts and bolts to loosen.

Does your muffler just screw into the engine or does it attach with 2 or more bolts?

If you have a screw in style you can use a lock nut, usually an electric conduit nut will fit, and use the nut to mechanically lock the muffler in place.  Just install the nut on the threads, all the way to the end, then screw the muffler in as far as it will go, then use pliers or a punch and hammer to tighten the nut...it will keep the muffler from backing out.

Eric