WR450F exhaust?

5 replies to this topic
  • Valkman

Posted November 08, 2003 - 10:10 AM


If I take out the stock plug on the exhaust, do I have to put something else in there or can I just run it open?? I have a WR450F. Thanks for the help

  • GrahamO

Posted November 08, 2003 - 10:20 AM


Open is fine. You might need something for noise regulations, like a PMB or GYT-R insert.

  • jim-in-so-ore

Posted November 08, 2003 - 12:12 PM


Go ahead and run it open, and when your riding area gets shut down due to excessive noise, you can be reminded of what you used to have. Like the man before me stated get the GYT-R or the PMB insert. Don't be one of the one who are responsible for us losing our riding areas here in Oregon. The legal limit is 99 db and I think that the open WR pipe is some where around 101 or 102 db. Way too loud. OK, OK I'm down off of my soap box now.
Oh, by the way, if you want to have a loud bike, buy a Harley, Those guys can seem to run no mufflers at all and get away with it. :)

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  • endurodog

Posted November 08, 2003 - 02:35 PM


You can run it open, the DB's from running it open are actually up in the 107-109 range.

No areas have been shut down because of noise, they are shut because of other issues, i.e. owls, errosion, tortises, ect. But the legal limit is 99 DB so you need to think about that so you don't get any tickets and it doesn't hurt our argument about keeping areas open if we can be a little quiter.

The inserts will get your bike down to the legal limit but you will be giving up some performance. Another, more expensive option is to go with a whole exhust system. I run a FMF Q. It gets it legal and has better performance than either the GYT or VOR tip I tried. Still not like an open exhust though, but I'm legal.

  • Valkman

Posted November 08, 2003 - 03:41 PM


Jim, Thanks for the comments.. :D FYI, I wasn't wanting to run it open for the noise just the performance. Nor did I know that running without the "plug" in the exhaust would make it over the DB limits. That is why I ask these sort of questions in this informative forum before I try something. :) I don't want to be the person that does something to mess it up for all of the others out there. :D I also don't like things loud, that is why I bought a Honda Valkyrie instead of a Harley. The six cylinders purr a lot more quiet then 2 big a$$ pistons with open exhaust. :D To get back on the subject and back to the second part of my question... So, if I buy the PMB or GYT-R inserts will I have to do anything to the jetting, or is that only if I put a totally different exhaust on it? :D Thanks again for all of the help.
Take care Jim, maybe if I'm in Cental Point we can hook up and ride together. I would love to see the county side over there. :D

  • jim-in-so-ore

Posted November 10, 2003 - 06:55 AM


I am using a 160 main jet, a 48 pilot jet, a 72 starter jet. The needle on the 4th clip from the top and the fuel screw out 1 3/4 turns.. The fuel screw may be slightly different for you as you are closer to sea level than me but I'm guessing only 1/4 turn or so.
Good luck (By the way, I'm no jetting wizard)



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