How to make my muffler more silence



I have a Zenoah Komatsu G23LH engine with the original muffler which is very noisy.
Is there any known way to make this muffler more quiet, without reducing the engine performance?
The friction wheel I've made with your help, is working great.
Thank you.
Is your engine a 2-stroke or a 4-stroke?

Ordinarily you can just make a bigger muffler for a 4-stroke, anything made from decent metal will make a big difference, the more internal volume the better..... but muffler/exhaust design is a lot more critical on a 2-stroke.
2 stroke

Its a 2 stroke 22.3cc Zenoah Komatsu engine.
With a standard small square muffler.
Can I make changes in this muffler, its quiet empty in side, may be its possible to put some kind of material inside to reduce the noise?
did you look at the link alaskavan gave you? maybe take this over there & ask for help?