Title says it all really.. The muffler came with the bike, but for me (and the neighbours) I think the noise is too much. I don't like opening the throttle too much, it's that bad.
So my question is how should I quieten it down? The end of the muffler is like the pic



I found on some sites a "quiet insert", has anyone had any luck with these?
How about packing? Will this help with the noise?

Any advice appreciated... except earplugs

 

Of course, if it has a "quiet core" available, that's the obvious place to start. Also, you cold put a cap on the inlet to the end-pipe....force the exhaust through the perforations, rather than let it rip right down the center of the end-pipe. What this will do to the sound and/or performance: I don't know.

 

I was just complaining about my M7 and how I noticed a looser packing of the stainless steel pot scrubbers (not steel wool) seemed to help a tiny bit.

I agree with Blackheart, it is my belief that if the straight flow of gas is not redirected then no significant sound reduction takes place as most gas and sound just blows by the packing no matter what packing it is. If you want it real quiet I'd cap the center of the insert's inlet, drill more holes in the sides of the insert, and then have a loose packing of pot scrubbers because fiberglass will just blow out.

On my M7 I safety wired a stretched out half of steel pot scrubber in the the middle of my muffler so the gases and sound were broken up. This would be cheap try for quieting your muffler, you'd be out $3, why not.

This is all theory so believe what you will, but if you look at jpegs of quiet mufflers, there's never a straight through gas flow, there's always metal baffles in the way making the gases turn.

 

Thanks for the replies.
I checked a few sites again and found this pic


The insert on the right is for the T4, seems the same as mine, just has the middle of the pipe blocked off as suggested. It should be easy to fabricate a cap for the end, I'll try that first.

 

Right, after researching I found this which is supposedly a "silent bomb" insert for the T4.



So, made a quick attempt (read hack job) to see what effect some added material would have on the noise. Sorry, having issues resizing with photobucket
First I added some small steel mesh...



Next I added a (rough) blank piece similar to the "silent bomb" part.



Conclusion.... only 30 minutes experimentation, but, no difference, maybe the exhaust note changed, but still window rattling loud. Without serious redesign of this muffler, I don't think I'll get it quiet enough. I don't want to shell out $30 ~ $40 for an insert which does nothing, so I'll look around for a new muffler...

 

It looks like your mod would've done the job, I had a similar setup once and ended up hammering the pipe size down after a failed attempt with steel wool blowing out.

 

I think the "add ons" would have lasted, just not effective enough in reducing noise level. I've no idea what the noise level is with these mufflers, JMCA approved units run less than 90db.

This is the basic muffler



With "quiet core" installed



I think something better is required

 

Talk about straight through, you're right, that definitely does not look like a JMCA approved muffler! How about cutting a Georgia Coffee can (or some other steel can) open and shaped into circle that fits those bolts at the end. You can keep poking holes in the can till it your acceptable sound level? All this can be done with a 110yen drink and 105yen scizzor, and you can buy all at the 100yen store.

 

I may try something else, but seriously looking for a new muffler now. Maybe 20+ years ago when I started riding the noise would have been fun, but not now.
Any ideas on reasonably priced Japanese brands? I've seen Beams units in my price range, or Nojima? Definitely must be JMCA approved, I'll be deaf soon if I don't do something.
I'll sell the FMF to a bosozuku kid

 

Repack it!