Question: The muffler on the VMAX 46PRO and 52PRO has a long bolt that runs through the muffler from end to end. It has a nut on each end. This sometimes loosens up. How do I keep this bolt tight?

Answer: Install a lock washer and thread locker such as Pacer Z42 to each end of the muffler bolt and re-tighten the retaining nuts.

Better Answer: 2 Stroke engines vibrate by nature of their compression cycle and unbalanced reciprocating mass. If you have an unbalanced prop and/or spinner the vibration is even worse. This vibration is accentuated in the muffler due to it's low mass and the extended offset distance from the source of the vibration. Nuts and bolts in mufflers may loosen due to this high level of vibration. To prevent the nuts and bolts from loosening, balance your prop and spinner, install lock washers on the bolts and use Pacer Z42 thread locker on the nuts and bolts. Check frequently for tightness.