Fixing the 08 yz450 muffler


20 replies to this topic
  • gdbarr1976

Posted February 08, 2008 - 07:49 AM

#1

I think we all can agree that the 08 muffler doesn't work. But, seeing that I really don't want to spend any more money my question is this...Has anyone tried to take out the inner cones? Did it help? Also, I have a power bomb from my 06 which doesnt fit the 08. Where it connects to the silencer it is to small. If I shim it up to make it fit any problems? I am going to try all this this weekend but was hoping someone allready has which might save me some time.

thks

  • lavens763

Posted February 08, 2008 - 10:45 AM

#2

yeh, the best thing about the 08' silencer would be to lose it. On the cheap side see if you can find an '07 it'll bolt right up and make a world of difference for sure. I actually cut three inches off of mine in '07 for a little more low end and it works fine with the 08. three inches was the magic number since fmf silencer repacking kit fits it perfect when it's time to repack it. good luck

  • gdbarr1976

Posted February 08, 2008 - 01:04 PM

#3

From looking at the picture in mx action pg 92 of the inerds of the 08 silencer it looks like with a little surgery I can cut out the baffels and will be left with the same as a 06/07 silencer with about 3" cut off. Shirley someone has tried this.??


yeh, the
best thing about the 08' silencer would be to lose it. On the cheap side see if you can find an '07 it'll bolt right up and make a world of difference for sure. I actually cut three inches off of mine in '07 for a little more low end and it works fine with the 08. three inches was the magic number since fmf silencer repacking kit fits it perfect when it's time to repack it. good luck



  • grayracer513

Posted February 08, 2008 - 01:44 PM

#4

Shirley someone has tried this.??

Surely, if they had, we'd have heard of it, and stop calling me Shirley.

  • matts06yzf

Posted February 08, 2008 - 01:46 PM

#5

Take that baby and put it on a nice shelf and never look at it again until you go to sell it :busted: Its ashame we have to do this but that pos will never go back on my 08 as long as I am riding it. Get a Dr D Or anything for that matter and be done with it. :worthy:

  • usp4u

Posted February 08, 2008 - 01:48 PM

#6

umm, arent you gonna end up with an extremley loud bike?
and dont call me "Shirley".
damn, grey beat me to it.

  • gdbarr1976

Posted February 08, 2008 - 04:11 PM

#7

Well Shirley, have you done this?

It doesn't really matter now. When I got home a check was in the mail for $311. It was a refund for a over payment of a medical bill in 2006 and the best part is I checked the mail before my wife. Time to start shopping for a pipe!

  • todds924

Posted February 08, 2008 - 08:17 PM

#8

I think we all can agree that the 08 muffler doesn't work. But, seeing that I really don't want to spend any more money my question is this...Has anyone tried to take out the inner cones? Did it help? Also, I have a power bomb from my 06 which doesnt fit the 08. Where it connects to the silencer it is to small. If I shim it up to make it fit any problems? I am going to try all this this weekend but was hoping someone allready has which might save me some time.

thks


That powerbomb will work!!! What you need to do is get a new gasket for where they fit together. An 06 gasket stuffed in the 08 silencer. I used the stock 08 headpipe and a stock 06 silencer on my 08 and it worked great.

  • gdbarr1976

Posted February 09, 2008 - 06:53 AM

#9

Since it won't cost me anything I am going to dissect that muffler, take out the cones and shim up my power bomb to make it all fit. Will it be loud? I will let you know.

  • TahitianRed

Posted February 09, 2008 - 12:46 PM

#10

Here is what you will find after you pop the rivets.



Posted Image

Posted Image

After you remove the cones (maybe just the yellow one?) it looks like you will need to use packing material arround the baffle tube.

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  • grayracer513

Posted February 09, 2008 - 01:04 PM

#11

You will find packing in there now. It just isn't shown in the cutaway.

  • psmith85

Posted February 09, 2008 - 08:17 PM

#12

While I found the muffler to be restrictive, I went up 4 sizes on the main jet with the stock pipe and found this to have a nice increase in the power.
Unless you are just dieing to spend money on a pipe, I suggest that you break out the MJ's and start jetting.

  • MC214

Posted February 10, 2008 - 01:39 PM

#13

I agree though ,put that stocker in the shelf and regardless what pipe you buy you won`t regret it.TIP: If you buy a dr.d it will let you run their rad.lowering kit.Which help`s handiling a ton.

  • wolfie12

Posted February 10, 2008 - 05:04 PM

#14

While I found the muffler to be restrictive, I went up 4 sizes on the main jet with the stock pipe and found this to have a nice increase in the power.
Unless you are just dieing to spend money on a pipe, I suggest that you break out the MJ's and start jetting.


4 sizes richer?!?! What is your rationale, or are you going by seat of the pants? Not trying to be a smart ass btw.:applause:

  • 201fastguy

Posted February 10, 2008 - 07:31 PM

#15

I bought a stock 07 silencer off of ebay it bolted right up with the 08 header pipe. The results where that now I have some bottom end and more power when compaerd to the stock silencer. I still want to try a Dr.D exhaust system when I can to compare and I'm sure that a Dr.D system would be better but for the cost I can live with what I have since I have $35 into it

  • team-tuareg

Posted February 17, 2008 - 09:12 PM

#16

Any performance results after those inner cones removed mods?

Thank you!

  • MXHSRACER

Posted March 02, 2008 - 02:27 PM

#17

I am slow Rider, but I like the look of the smaller exhaust, are any of the after market exhaust short?

How does the short stock exhaust preform?

I just saw a guy today smoke the 250 B class on a stock 08 YZF450

I know the rider really makes the diffrence, Being that I suck, would It matter if I keep the stock one one, What the best set up for the stock exhaust?

I am slow, and not a huge rev'er, might even short shift a bit, whats good for me? To have a good low to med range power but smooth?

  • wolfie12

Posted March 02, 2008 - 07:17 PM

#18

I think Yamaha was going for usable power with this setup, which pure racers should appreciate. I haven't gotten to use my new bike yet, but am definitely going to try it stock for the first couple rides. The thing is, if you don't have to spend as much time fighting the bikes power, you can concentrate on carrying more speed.

  • 02YZ426

Posted March 26, 2008 - 02:08 PM

#19

Is the 08 muffler really kill the power or something? I just bought this pipe to replace my smashed one on my 07.

  • erickdj

Posted March 26, 2008 - 02:17 PM

#20

Is the 08 muffler really kill the power or something? I just bought this pipe to replace my smashed one on my 07.


yeah, it really kills it. you'd be better off finding a used one from an 06 or 07 from ebay.





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