Any suggestions for really quiet engine/muffler combinations? Power secondary to noise but enough to fly a sport stunter. Ideally up to .40 size

Any suggestions for really quiet engine/muffler combinations? Power secondary to noise but enough to fly a sport stunter. Ideally up to .40 size

Hi

You can use most any of the  OS engines or  Magnum Thunder Tiger  motors  that use a  baffled muffler, then  add a  silicone exhaust  extention. These really help take the noise  off.
The props will also  help lessen noise, a  3 blade is less  noisy  than a  2 blade  and  the  scimitar  shaped  tips  will also  help  in  noise  abatement.
Add all  these  up  and  it will be  very quiet

Randy

Saito .30 or .40 running at 8000 rpm you can hardly hear it. Most two strokes with restricted muffler running at
lower rpm 7000-7800 are less noisy. The reason that most people cannot use a quite muffler is that they are
running too high rpm and with a restrictive muffler you have to lower the rpms considerably I have a
Discovery Retro .60 VERY quite but designed to run at 7300-7500 RPM.

If you don't like the OS baffled mufflers(20-30,30-30) you can try to get the K&B 45 muffler.  It can be fitted pretty easily to most 40 size engines.  The K&B muffler is very quiet and can even be tuned by adding a stiff silicone plastic tube on the end.