Steve, hope that your not "-----" off.............................
Appreciate info....................................................
Do tell me what you have? I'm 48cc 26" MTB
No, not p'd off at all.
The reasons that you need to use a descriptive title are twofold.
Without an appropriate title, you're not likely to get relevant replies, if any at all.
Also, in future when people search for help on a topic, this thread has been a complete waste of time, because 'How can I .............' isn't relevant to anything.
Titles like 'Problem', 'Silly Problem', 'Need Help' etc are equally abstract.
It really is worth thinking carefully about the title of threads, for everyone's benefit.
I'll get off my high-horse now.
An expansion chamber is the best pipe to improve performance, at the cost of a bit more noise. I'd fit one, but it makes an MB look a bit more like a motorcycle and might make the cops take notice.
I'm not familiar with the solid black muffler. No screw in the bottom or other means of dismantling it?
Mine has a screw in the bottom, holding the end-cap with the tail-pipe in place.
I drilled two 4.5mm holes right through the tail-pipe, not far inside the end-cap to increase flow, but otherwise it's stock.
If your's
is solid and you have no way of pulling it apart, logic tells me that either an expansion chamber or a stock muffler that you can pull apart and modify are your only real options.
(Unless there are other pipes that I'm unaware of. There's the poo-poo pipe, not sure who sells them, but I think they're just a stock muffler on a long header pipe - improves bottom-end but decreases top-end power.)
I'm not sure who else sells expansion chambers, but my experiences with SBP are hard to beat.
... Steve