I really enjoyed flying RC in days before mufflers were used and like many I went through all the pain and anguish clubs experienced mandating mufflers in the late 60s. At the time the Descent almost destroyed our club. The un-muffled engines had baffles that closed over the exhaust port as the throttle was retarded and they ran very strong and idled like a dream. Many of us few at public fields and gave up flying at the club fields until the muffler technology improved. You get more power without a muffler and less engine heat buildup. The real solution to mufflers is to use a tuned pipe so you get more power and low noise.