Hi, newbie here. Been searching for some answers to a few questions i havent found and hoping someone can help. I just picked up a 2007 KLX 250S, did the msf, licensed, the whole deal. love it! curious of a few things as I start playing with my new toy:

1. Will any of typical mods run risk of me not passing annual inspection for some reason that anyone is aware? I live in VA, and we have no emissions testing. I am planning on doing the free mods now and hope to do a big bore kit, new exhaust and possibly new carb within the next year as i grow into it.

2. I am looking into exhaust change out. I was wondering if anyone can suggest a good close to stock quiet pipe if that is even possible. With the thought that I may do a big bore in the future, curious if that changes recommendations. Dont want to **** off the neighbors too bad, and if i go stealth on some local trails, dont want to attract attention to myself if I can. I looked at PlanetKLX and went over the exhaust info and read up on what i can. I am leaning on buying a 300 header and pipe that i can remove the plug from or going with the FSW header and pipe because of my concern for noise (showing <90 db supposedly on the FSW, with good increase according to their review). Does anyone run the FSW system that can comment? is the Stock 300 setup (header and exhaust) close to the same db level as the 250? with the plug removed is their much additional noise?

The other alternative is if any of the 250s exhausts have removable plugs on them. Mine appears to be welded, cant find if that is uniform across the board or not.

Thanks for your help!
Matt

 

Any of the pipes will increase the noise considerably, even the stock 300R pipe with the plug removed. Staintunes pipe is rated to 92 dB FACT, although exxy for you guys in the USA, looks great too BTW. All the others are loud. Muzzy, Big Gun and Two Brothers rule in that dept. For stealth, it's the stock followed by the Staintune then the FMF Q4 IMHO.

I have 300 header and Two Brothers M7 pipe. It's farkin load. I like it, it scares the **** outta the roos. Haha.

No air box lid makes it louder.......but faster.

 

Like west oz said if you have anything but the stock exhaust it's going to be loud. I have the 300 header and can and although it's alot louder than the stock can it's not as loud as some aftermarket pipes out there. I love the sound of it and it's also the cheaper option...I spent just under $100 shipped from e-bay.

 

ive been looking for the 300 stock pipe on ebay. Hard to find any. i have a chance to get an FMF Q4 with 300 header for around 175 from a bike being parted out. my understanding is it is close to the 300 stock pipe in db.

anyone know or have heard anything about the fourstrokeworks system?

also any idea if i want to have someone put in a big bore kit what a reasonable install price is labor wise?

 

Guessing $400-$500.

 

Do it yourself, if I can do it anyone can. Besides putting in new shims for the valves is almost as much work. You can do it.....it's easy.

As far as exhuasts go....what about that Q4....I've heard ( well not heard but has been reported ) to be a lot quieter than my muzzy or a big gun....is that true guys?

 

I think the Q in the Q4 actually stands for quiet, and I think I read somewhere that FMF developed this quieter muffler to help riders keep a lower profile. You get too many noisy bikes in any area, and the non-riding public will start to complain, especially if you are on public lands. I love my Q4. I wouldn't say it's too loud, but it does give the bike a nice low thump, just what I was looking for.

Dan
Edit: Never had it next to a muzzy or big gun, but would guess the Q4 is a bit quieter.

 

I installed the FMF Q4 three weeks ago then rejetted the carb. The muffler is pretty quiet unless your under full throttle. Sounds cool at idle and was easy to install except having to re-silicone the exhaust to header connection because it was leaking after the first try. I put the muffler on before rejetting and noticed some power gain. But good lord what a different bike with a jet kit and the airbox lid off. I can do 60mph with little throttle. All stock I was at 3/4 throttle to do 60mph.