Muffler/Silencer for MZ expansion Chamber

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KTOKTO

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I recently purchaced the MZ Miami expansion chamber like this one.

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The thing is crazy annoying loud, so loud I would never drive it in town. I was talking in another thread about a muffler solution. Some have either welded a stock or aftermarket muffler on the end of the MZ pipe.

After looking around I found this little universal Supertrapp type of baffle...

https://www.amazon.com/Motorcycle-E...fle+DB+Killer+Silencer+Noise+Sound+Eliminator

51WMCWZAF%2BL._SL1001_.jpg


It fits perfectly in to the MZ pipe. I needed to pound it in with some light taps with a hammer and dowel.It fits so nicely I dont think you would even need to drill a hole in the MZ pipe for the set screw.

25g5oqs.jpg


I have the adjuster set in the middle of of the pipe right now and it was a good reduction in sound at low RPM. It is still too loud though so I am going to bring the adjustment back a few notches and see what it does. Considering the size of the holes, I should be ablde to run it at the most restricted position just fine.

I am also thinking about wrapping the baffle with some fiberglass muffler packing and tying it down with some stainless wire.

https://www.amazon.com/Muffler-Pack...1572&sr=8-2&keywords=2+stroke+muffler+packing

It looks really nice, no cutting or welding needed on the MZ pipe. The only problem I have right now is the thing is set in there fairly tight so I am going to need a slide hammer to remove it to adjust. One note, I definitely need to add a lock washer and a drop of locktite on the adjustment set screw.
 
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I have a laser thermometer and a decibel meter so I will get a some db and running temperature readings with the stock pipe, the open MZ pipe, the baffled MZ pipe and the baffled and stuffed MZ pipe and report back in later this week.
 
Ok definitely keep us posted. I purchased the same packing for nearly half the price on eBay, might want to consider purchasing from there.
 
I took it out today with the baffle in the most restricted position. It is not terribly loud but still as that annoying pop to it. I wouldn't get pulled over just cruising around at 20mph. I have a shorty glass pack for a motorcycle coming in the mail. I am going to slip that on too and see if I can get rid of some of the pop.

As far as power, the MZ pipe does perform. No power difference down low but more mid range and a lot more up top.

The fastest I got it before was 41. I hit 44 today with this setup...

Skyhawk gt5
40T sprocket
dellorto clone
MZ square head
MZ expansion pipe
Me 220lbs

4 mph to 44 mph on one gear without missing a beat.

With that said, if the glasspack doesn't make the tone more neighbor friendly, I am going to go back to the stock muffler. I don't need the high end gain that bad.
 
Thanks for the info on the baffle. I just ordered one and the fmf 2 stroke packing to try out. If this works it will save me a lot of time
I wish I new the volume of the head your using. If it's a 8cc chamber you can deck the jug till it is 2.710" to gain some low end torque. These are mm measurements of a stock jug in the pic. but they show the points to measure from. Just so you know , if it is a 8cc head this decking will bring the compression up to where the stock slant plug head was. If it is a 6cc head your compression is going to be really high, like in the 180 + range. It would be best if you used the solder gauge to set the squish gap. Then you know your not pushing your luck. Dam compressor just fired up and scared the s**t out of me.View media item 60633
 
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Thanks for the info on the baffle. I just ordered one and the fmf 2 stroke packing to try out. If this works it will save me a lot of time
I wish I new the volume of the head your using. If it's a 8cc chamber you can deck the jug till it is 2.710" to gain some low end torque. These are mm measurements of a stock jug in the pic. but they show the points to measure from. Just so you know , if it is a 8cc head this decking will bring the compression up to where the stock slant plug head was. If it is a 6cc head your compression is going to be really high, like in the 180 + range. It would be best if you used the solder gauge to set the squish gap. Then you know your not pushing your luck. Dam compressor just fired up and scared the sh*t out of me.View media item 60633

There is no need to mess with the motor itself right now. It has loads of torque the way it is. One push of the pedals from a stop and it takes off like a champ.

The head is 6cc and compression measured at 130.

Here is a picture of the chamber.

s-l1600.jpg


The only issue it has right now is it will 4 stroke from time to time when not under load no matter the jetting. Jaguar is sending me one of his CDIs so I am hoping that will remedy some of that.

And ya, I tend to leave my compressor on over night a lot with a tool plugged in and it wakes me up all the time. You'd think I'd learn.
 
130 psi is really bad for a 6cc head. check your squish
I dont think that it's 6cc most all the chinese copies are 8cc and on a grubee that sounds about right the stock slant head can come in at 155 and if decked 180ish!
 
I dont think that it's 6cc most all the chinese copies are 8cc and on a grubee that sounds about right the stock slant head can come in at 155 and if decked 180ish!
I have the same MZ square head, it was advertised as 6cc but I think someone said it may be larger?? Does the same psi still apply?
 
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