Muffler/Silencer for MZ expansion Chamber

[KTOKTO]

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 could be wrong.. I'll take a look at it the next time I have the head off.

Thanks for the info.

 

[Street Ryderz]

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?

The p.s.i can vary between one engine to another having the same 6cc or 8cc head due to varients of deck height and squish affecting the compression!

 

[butre]

What is the right psi for a 6cc head?

160-ish

 

[gary55]

At 5400 ft the 6cc head is around 135, so 160ish is about right for near sea level. It sounds like many of the other heads advertised as 6cc, but are really 8 cc. It would explain 130.

 

[KTOKTO]

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

WE HAVE A WINNER!!! The muffler packing knocked the sound dead on it's ass. Plus it has a really cool tone to it now.

What I did for testing was left the baffle in the most restricted position and cut a piece of packing the length of the baffle minus the holes in the baffle the exhaust passes through. I then trimmed the piece so it wrapped about 7/8 around the baffle, leaving a little room for exhaust gasses to pass. Then temporarily tied it down with some wire through a couple of the baffle holes.

My god what a difference.

I went for a few mile ride and pushed it up to 40mph for a couple stretches, then idled home a couple blocks. The jug temp measured at 350 degrees. I will take the thermometer with me next time so I can get a reading after a long high rpm run.

Since it is so pleasant right now, my plan is to move the restrictor open one more setting, cut a little more packing material out to give it a little more free flowing area, and then wrap the packing in some stainless screen to keep it held together.

VERY VERY VERY VERY happy with the results.

 

[KTOKTO]

Also, you are going to need some way to get the baffle out of the MZ pipe for when you tune or when you need to re-pack. I took a piece of steel rod that fit inside of one of the baffle's hole and bent the tip in to a hook that grabs on to the baffle holes when it is in the pipe. Then on the other end of the rod, I bent it 90 degrees to give me something to pull and tap a hammer on to pull it out. I had to wait for the pipe to cool down before I could remove it. It fits in nice and tight when the pipe warms up.

 

[gary55]

Also, you are going to need some way to get the baffle out of the MZ pipe for when you tune or when you need to re-pack. I took a piece of steel rod that fit inside of one of the baffle's hole and bent the tip in to a hook that grabs on to the baffle holes when it is in the pipe. Then on the other end of the rod, I bent it 90 degrees to give me something to pull and tap a hammer on to pull it out. I had to wait for the pipe to cool down before I could remove it. It fits in nice and tight when the pipe warms up.

I feel like the guy in the picture . Now I can't wait for the stuff to get here.

 

[KTOKTO]

I feel like the guy in the picture . Now I can't wait for the stuff to get here.

I got the packing material wrapped in aluminum screen and secured down wih a couple pieces of wire threaded through a couple of the silencer holes. I have the baffle set in the 2nd most restricted position now. Let us know how you get yours set up and your thoughts. Thanks.

 

[KTOKTO]

I found a different style of baffle the works much better

http://www.ebay.com/itm/8-Long-Baff...ash=item4afe1bd1a9:g:-GQAAOSwwbdWGVIR&vxp=mtr

I wrapped this in the muffler packing and then wrapped that with aluminum screen and tied it together with some stainless wire. Slid right in and sounds and performs great!

 

[Tony72373]

You guys are lucky. I've been trying to get my order from MZ since April 7. Calls and emails are answered but with them stating a new store and warehouse move I've been patient with not getting a PayPal invoice yet. I'd use their ebay store but shipping costs on a few parts are messed up. Ie: replacement reed valve... $31.00 shipping. Complete lower engine.... $14.00 go figure? I don't want to buy from someone else.