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gdbarr1976

Fixing the 08 yz450 muffler

21 posts in this topic

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

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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

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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

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Shirley someone has tried this.??
Surely, if they had, we'd have heard of it, and stop calling me Shirley.

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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:

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umm, arent you gonna end up with an extremley loud bike?

and dont call me "Shirley".

damn, grey beat me to it.

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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!

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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.

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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.

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

08YZ450Fmuffler1.jpg

08YZ450Fmuffler2.jpg

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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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.

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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.

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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:

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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

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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?

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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.

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

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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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