I decided to go with a KLX 300 Exhaust on my '09 250, so I have the usual jetting questions, plus a butt plug question. First, I haven't gotten the exhaust yet, just won it on ebay a couple of days ago.

Looking for opinions from other '09 owners who are running the 300 exhaust (and header). I am at sea level (or close to it) 95% of the time. I am thinking 128 main, 35 pilot. Does that sound right?

Also, the exhaust is coming without a butt plug. Can someone take a picture of what the stock inards look like? I see a few different options on ebay, but not sure which is closest to stock (or does anyone have a stock plug they want to sell cheap )? Here is a picture of what I am getting, so I assume the butt plug is missing (the seller really didn't know anything about it, just something he probably picked up to resell).



Any info would be great. Also, I will probably have an extra 300 header, if anyone is interested, just pay the 20 bucks that I paid to get it to me originally (I won the whole exhaust/header about a week after i bought just the header). Although I should probably just keep it, since i mashed the original header on the 250 on my very first ride

 

Do not worry about using the butt plug. The hole through it is so small that I can't get my little finger through it. Without the butt plug, my KLX300 was measured at 93db......legal on public lands.

Ride on
Brewster

 

at our last Dual Sport event the only bike that did not pass was a KLX300, stock pipe no but plug, measured over 100db, very loud, I know mine without my custom plug is very loud, but with the custom turn down plug it is about 90db. still runs great but without the plug the bike is VERY LOUD.

 

thanks for the replys. any thoughts on jetting?

 

Stock #35 pilot and #132 main jet. Raise stock needle 1.5 mm with shim. Fuel screw about 2 turns out from lightly seated.

 

great, Thanks!

 

Without some sort of downturn tip a KLX300 pipe is WAY, WAY loud. Too loud. I'm guessing 100db is about right. This weekend I'll have a chance to sound test mine, would be totally surprised if it came in under 96db "open ended".

I designed and built a custom down-turn cap for mine (sorry no pic at the moment). I'm 95+% confident I gave up nothing power-wise or if I did it's trivial compared to the decibel reduction.

As far as jetting ... I'm at 4,800ft here so my settings are useless to you. I'm running a 120 main, KLX300 needle 2nd clip from the top, stock pilot jet, K&N air filter, KDX200 snorkle on the air box.

Sea level ... yeah, 128 to 132 main, stock pilot jet and a little experimenting with needle position.

 

I run the klx300 pipe with one of those billet downturn endcaps that a guy on ebay sells. It knocks the sound down some and is fine for most rides. If I want sneaky quiet I throw the stock peashooter back on. The stock end cap is nothing fancy, you could make one pretty ez. KDX snorkle, K&N filter, 132 keihin main (128 was too lean) stock 35 pilot and a 300 needle on the 3rd notch. They all jet a little different though, and I'd try shimming the needle before buying a new one.

Big difference I notice between the stock peashooter and more open endcap. Say your grinding up a steep 1st gear technicle climb in 2nd gear (you should be in 1st), with the corked pipe if you roll on it'll make the bike fall flat on it's face and force the downshift. With the uncorked pipe it'll just pull harder and run out like it's supposed to.

 

I also run the klx300 pipe and muffler with billet straight endcaps. It is fine for most rides and being a stock can I have the stock peashooter if I need to pass a DB test. klx300 with large butt plug makes the bike sound like a much larger displacement bike. Sound great - runs hard and I would not trade this system for any after market pipe (but that is just me).

I agree with you, they all have a personality that needs to be fine tuned. Uni Filter, KDX snorkle, Kawi OEM Needle N1TC needle (clip in second from top notch),Main Jet 130, Pilot Jet 38, Carb slide drilled 7/64", Idle screw 2 turns out, de-smoged.

I had a 125 main jet in and it ran terrible.

Last weekend, Benron, one of the guys in the group - you know the smooth guy who can do anything on any bike took took turns riding everyone's bike including some 450. His verdict was the my klx250s was the most fun. In defense of the other bike, mostly they needed gear changes or were to much power for that type of riding.

It was cool to see Benron make that bike do what it can do. It made me feel bad as I will never be able to ride like that, but Benron has no fear and is exactly half my age. It reminds me of Dan888 riding two loops of the Leaf River and me just one. Or my GF's son riding my bike and being the second guy to the lunch spot on the Kettle Moraine ride.

Set up properly this bike will make a slow or fast rider content.

 

ok, thanks for all the great info. I just need to figure out exactly what to do for a butt plug, since mine came with nothing (wide open).