Muffler Insert

110 replies to this topic
  • Indy_WR450

Posted March 12, 2003 - 06:53 PM

The extra back pressure from the insert should allow for leaner jetting from the main jet and needle position. But that is only if you were jetted right to begin with the bike completely uncorked.

  • RonO

Posted March 14, 2003 - 11:35 AM

Just returned from a ride with the new insert. (Had to go get a new WV Inspection) The bike runs much better with the insert than wide open, I'm still running stock jetting. It's very easy to snap into a wheelie now from low rpms. Mine didn't seem to want to do this with a wide open exhaust. Also, I had a high end miss that is now gone. I'll test it more Sunday.


  • Fryboy

Posted March 15, 2003 - 04:06 AM

Well I finally got my insert in yesterday!!! I installed it in 5 seconds. Started up my beast, a little bit tamer, but a lot better than the stock baffle. Sounds a bit better too. I actually can get my bike to idle without hanging. This is a tough thing to do with the stocker. I buzzed the neighborhood once to see how it was. I have mixed emotions. On one hand I am happier with this than stock, on the other, I still feel all corked up. But, to be fair, I haven't taken it out for a real ride. I will report later.

P.S. One of these days I will find a pipe I like as much as the stock pipe uncorked which meets sound req. Until then this will have to do. A $43.05 band-aid


  • Indy_WR450

Posted March 15, 2003 - 04:23 AM

I agree with Fryboy. The baffle is still restrictive for wide open throttle but the bottom end and midrange are very good. The noise level is fantastic. I have both the Baha and GYT-R baffle and can not tell the difference other then in my wallet.

  • ddialogue

Posted March 15, 2003 - 05:24 AM

It sounds like we may need to lean the jetting up again since the muffler insert restricts. One person on here (can't remember just now who it was) said that once he leaned it back up a bit it was just like it was fully uncorked. So, don't give up on it just yet... :)

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  • Fryboy

Posted March 15, 2003 - 06:18 AM

I won't give up! I am in it to win it :)

Being I haven't touched my jetting and/or fuel/air mixture I have to agree. It can possibly get better. More likely than unlikely. I will keep my eyes on this post and see if any of you get it dialed in better. Keep tinkerin guys!


  • Rich_in_Orlando

Posted March 15, 2003 - 12:48 PM

I rejetted after I installed the insert-it went from and EMM #1 needle to a DTM #1 needle (it's a leaner needle) and increased (surprisingly) the mj from a 150 to a 158. It runs better now than it ever has. I messed with the needle first to get rid of a serious mid range bogging problem it developed after installing the insert. I am really pleased with the bike's power and reduced noise output with the insert in now that it's finally jetted right.

  • MxnDoc

Posted March 15, 2003 - 05:42 PM

Have any of you TT'ers used the D1 (5TJ-14916-D1) needle with your GYT-R inserts? The owners manual (page 7-8) lists it as the "except for USA" standard. Are we all still "on the same page" regarding jetting with this insert? Any advice would be appreciated!
Bob :grin: :)

  • MxnDoc

Posted March 15, 2003 - 05:45 PM

That is regarding the WR450!

  • Yamichick

Posted March 20, 2003 - 09:25 AM

The correct part number is:
Fit's all '98-'03 WR's.
A picture will be up by the end of the day

  • MorrisWR

Posted March 28, 2003 - 07:58 AM

I just ordered one from Snake River Yamaha. $39.95 + $5 shipping. They said they have a few more in stock. Here's the number if anyone still needs one. 1-800-467-1093. They know what you're talking about if you just ask for the Yamaha exhaust insert.


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