stk exhaust cone removal 09 yz540f

Need some directions or pictures on removing the "2 cones" from the stock exhaust to give it a little deeper sound, and a bit more power

The problem with doing that is the header is too large of a diameter for a regular type flow through muffler. You will get less power and a lot more noise.

The problem with doing that is the header is too large of a diameter for a regular type flow through muffler. You will get less power and a lot more noise.

That seems to be something that's up for debate, some guys here swear that by removing the cone attached to the endcap they're getting more power out of the bike. Someone could agrue that if you only lose power, then mounting up an aftermarket slip-on to the stock header won't get you any more power either. Which is completely false.

My buddy just installed one of these Lexx slip-ons onto his new '09 yz450f and he's very happy with it ($179 shipped) :

http://cgi.ebay.com/ebaymotors/Lexx-Exhaust-w-MidPipe-YZ250F-YZ-06-11-YZ450F-06-09-_W0QQcmdZViewItemQQhashZitem3363296787QQitemZ220706989959QQptZMotorcyclesQ5fPartsQ5fAccessories

Read these :

http://www.thumpertalk.com/forum/showthread.php?t=851003

http://www.thumpertalk.com/forum/showthread.php?t=946325&highlight=cone

Pics :

http://www.thumpertalk.com/forum/showthread.php?t=958487&highlight=cone

It sounds like it has some advantages, but i do understand what your saying about the theory behind it.

I've decided to do it, if i notice a drop in power, then slip on it is. My question now is once i drill out both sets of rivets, Am I supposed to remove both cones, or both cones and that perforated tube? THat second link you sent me has a great picture on the second page but doesn't go into the best detail about what is done.

The problem with doing that is the header is too large of a diameter for a regular type flow through muffler. You will get less power and a lot more noise.
It will be louder, but you misunderstand the power issue vs. header diameter. Removing the cones will give you an immediate boost in mid range (~5K) power. Because the header is oversize, the power increase could be greater if the right sized header tubing were used.
It sounds like it has some advantages, but i do understand what your saying about the theory behind it.

I've decided to do it, if i notice a drop in power, then slip on it is. My question now is once i drill out both sets of rivets, Am I supposed to remove both cones, or both cones and that perforated tube? THat second link you sent me has a great picture on the second page but doesn't go into the best detail about what is done.

So.... is this the way to go?

If I were interested in doing the mod, I'd remove the end cap and I'd cut the tube/perforated tapered end off.

yz450185913.jpg

drilled out the rivets, how do u get that sealant off? i mean how do you separate the endcap from the rest with the sealant holding it in place? razor?

drilled out the rivets, how do u get that sealant off? i mean how do you separate the endcap from the rest with the sealant holding it in place? razor?

With a big hammer, preferably a heavy rubber mallet. When i took mine out i had to keep hitting it from side to side. It takes a while, but thats how some of other guys on TT do it. I dont think there's any other way of doing it.

Yes, use a razor to slice the black sealant. I think its silicone.

ok, got that done it was a pain in the @$$, but its all out now... too bad I stripped the oil drain plug now... F me..

Now would be a good time to replace the muffler packing while you have the muffler apart. BTW, where in WI are you?

GB, i already put her back together

Now would be a good time to replace the muffler packing while you have the muffler apart.

Good call.

It is better now than a couple of years ago but there obviously still people out there that don't yet understand the performance gains that come from a fresh repack not to mention the accompanying db reduction.

forgot to mention my bike is brand new, the packing was still all white

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