Which Exhaust

Are you folks using with your FSW header? :D


I have a SuperTrapp IDS2 muffler but I don't think it's being made any longer.

I had a Stroker muffler for awhile but it was too loud and required frequent repacking. I went back to the stock muffler. Slight loss of top end power.

I'd recommend putting your $$$ into the suspension instead of a muffler.

Ride on


Well if you runing the stock, what if any tip are you using?

Thanks for the replys! :D

Are you folks using with your FSW header? :D


The FMF Power Core IV seems to be one popular choice. I run a CRD "Absolute Power" muffler that I wouldn't trade for another. Noticeable gains from mid to high over stock. After the 1st 700 miles, the packing was still in good condition. Their are 1 or 2 new U.S. distributors, but not sure who they are.

Brewster has a good point though...if you haven't done the suspension, dial that in 1st , then the power...I wish I did :D

Good luck with what you decide!

Sangair :D

Just bend some 1" pipe and weld it to a flange, drill the two holes and paint it.

My son's bike has the stock muffler with the butt plug removed. I bought a stainless steel hand rail from Home Depot (~$20) and cut one end off. Then matched one of the mounting holes and drilled another.

This helps reduce some of the noise and keeps the exhaust away from the rear fender. Somebody did a post on this subject a while back. You can search for "Exhaust Tip" and probably find more information with pictures.

If not, let me know and I'll take a picture of my son's for you.

Thanks guys

I'd be interested in seeing a picture of the DYI homedepot exhaust tip.... :D

Big Gun race series

I turned one on a lathe at work and then anodized it black.

But before that I just left the end of the muffler uncovered.

Here's the post I refereed to earlier:


I haven't had a chance to take a picture of my son's bike yet. They're still dirty from the last ride and the bikes are inaccessible due to other home projects in progress. The post will give you what you need to make one or two.

I made mine a little bit longer than what's in the photos and it makes a noticeable difference in the exhaust note.

Here's a link for a stainless steel "Grab Bar" at Home Depot:

http://www.homedepot.com/prel80/HDUS/EN_US/diy_main/pg_diy.jsp?BV_SessionID=@@@@0208137986.1123012504@@@@&BV_EngineID=cccjaddffmkffekcgelceffdfgidgln.0&CNTTYPE=PROD_META&CNTKEY=misc/searchResults.jsp&MID=9876&N=2984+3842&pos=n25 I clicked on the link after I submitted it and you'll have to click on "Bath Safety" and look for the shortest grab bar you can get. If I remember right, when I went to my local Home Depot, the items available didn't quite match the website, but you get the general idea any way.

Make sure you get one with the mounting holes exposed or you'll end up having to weld the flange. This way you can make (2) and you'll have a spare to keep in your tool box! :D

im running a big gun race series full exhuast with the quiet core... it sounds and runs great.

Well if you runing the stock, what if any tip are you using?

Thanks for the replys! :D

If you don't want to deal with making your own tip, FSW has 'em.

2003 klx 300, white bros header stock can. I had to wrap the header with thermotec exhaust wrap because I burned my pants and myself (bad), but I also lets the engine run better when you tune it. I'm probably gonna keep the stock can because it is maintenance free and my klx is starting to turn into a well tuned, well running beater - it doesn't look good but it runs great. I sort of followed dave_carls lead on the turn down because I wanted the bike quieter. Here's what I did: also at home depot, I got an undersink pipe "elbow" with a wall flange for about $1.50, then I bent trimmed drilled and cut until I had an end cap I liked, put rtv between the can and end cap and bolted it on! From a distance it looks great, but up close you can tell it's homemade. But....It made the bike SO much quieter and less raspy sounding I was amazed at the difference! No loss in power.



Buy a metre or two of 38.1mm stainless tube with a wall thickness of 1.6 and bend one yourself using the original header as a template. You will have to machine up a spigot to suit the header pipe to the head but remember the outside diameter of this spigot has to have 1mm gap all the way round so a 2mm difference is ample from the step out of the exhaust port, you can use the original flange. The exhaust port is 38mm so this size tube you can buy readily from the steel shops is ideal. A good after market header and pipe I have been quoted at $800+ and thats too much for me so I am in the process of fabricating my own as I am fortunated to have access to tube benders etc and blokes who can weld tig very well. As for the muffler, well that'll be pretty straight thru, same diametre as the header pipe, 38.1mm, with the outer casing at 80mm and I'll just buy some muffler packing all depends on what you want to do really, I am using 80mm stainless but you could use ally if you want to save weight, I just prefer to use all the same material thru out the system and it'll be more robust. We dont want the muffler too restrictive nor do we want the engine to have no back pressure as this is where and how touque is created, this is why the standard muffler isn't really that bad!

I have a 96 KLX250 that I have just had sleeved and bored out to a 300, upped the compression slightly, standard is 11.0:1 and we'll give her about 11.8:1 so as we can run higher octane fuel, BP ultimate 98RON and have purchased a Keihin 35mm pumper carburettor and with the exhaust system I am fabricating it should be an absolute cracker.

The finer tuning will come later with jets etc... The only other mods will be a muffler tip that can be at the 38.1 outlet that we'll start with and come down smaller to get the best power curve, its all in the testing although if I had access to a dyno, that'd be sick!!

Anyways hope this is some help, once I finish my system I will try to post some pics!

Cheers and Beers!! :D

you stated elsewhere that you had a 2005 KLX 300, The Systems available that are Forest service approved are:

1) FMF "Q" Silencer KLX250/300 fits 94'-04' (05' also) for around $$$ 300

2) Pro Circuit T-4 Silencer w/Spark Arrestor KLX250 94-96 / KLX300 97-04 for around $$$ 320

3) Big Gun Evo X Series Exhaust Complete System KLX250/300 94-05 for around $$$ 450 to $$$ 480 :D

For the best value, I would go with the Big Gun EVO X series. It is a complete system, comes with a thermal coating in the pipe, Meets the AMA 102 db sound requirements in standard trim also comes standard with USFS approved spark arrestor and with the quiet pak installed is around 94 db. :D

I'm using the FSW header and the stock muffler. I've been real happy with it. Ran it for a long time without a tip ( took out the butt-plug) but after a while the exhaust starts to discolor the fender plastic. I've read that after a long time, it will actually warp the rear fender in a bad way so I took my original end plug to a muffler shop and they cut out the center and welded in a short mild turn section from a chunk of muffler pipe. Cost me (2) good six-packs. If you do something like that, make sure you get the hole alignment correct so the finished product ends up pointing down and/or away.

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