Jetting and Snorkel removal Questions after Dr D exhaust

I have a 2003 wr450 that has the free mods done, except the snorkle removal (bought it this way), JD jet kit, and Zip-ty fuel screw. It had the stock pipe with the pro moto insert until today. I installed the mid pipe and silencer from Dubach racing. It definitely is louder and feels like it has a lot more power from riding it up and down the street. My question is, Do I need to change the jetting because of the pipe? Also, now that I have exhaust, should I remove the snorkel? How much of a difference would there be and where would it be felt? More snap? More bottom end? top end? etc? Thanks for the help. :applause:

You need to do more then remove the snorkel. That does very little on 2003 bikes. With a better flowing pipe you want to put 3 or 4 1" dia holes in the right side airbox under the side cover. You can buy 1" foam air box plugs that will fit in those holes. Or if you dont like removing the snorkel get a Barnum Pro Products also makes a nice side cover screen and plate:


The stock bike is pathetically choked up on both ends! :applause:

You will need to rejet! Read the pinned jetting post on top of this forum:

Thanks Indy for the advice. I would assume that opening up the intake, by removing snorkel as well as the holes in the airbox, and the free flowing exhaust the power should be quite a bit better than stock. How is the power delivery affected though? I have only been riding DB's for 1 season now and I love the fact that I can tractor anywhere as well as haul A** when it opens up. I don't want to lose that easy power delivery that the bike has had. In other words, I don't want it to act more like a 2 stroke with on/off power. I struggle with that kind of power delivery because we ride a lot of trail, slippery, rocks trails and my throttle control is not great yet. I am also going to get a rekluse next which should help my stalling on very steep nasty trails where I always seem to stall. Thanks, Pat

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