A little bio first: I'm of (ahem) mature years and have been riding pretty much constantly since getting out of the Army in '71. I've gone through just about all the phases of two-wheeled life, from my first 250cc 2-stroke enduro to a behemoth 1500cc Goldwing with stops at everything in between including Harley and other touring cruisers, 100+ hp muscle cruisers, and a few naked bikes. In the era of my callow youth -- no doubt before most of you were even a twinkle in your daddy's eye -- 650cc was a monster displacement, so much so that when I rode a Suzuki TS-250 Savage from Ohio to the Yucatan in the early 70s it was no big deal. In fact I did it twice in consecutive years, if nothing else proving that I am a slow learner. So this new (to me) '09 KLX takes me back to a kind of nostalgic place. Full circle, as it were.

So why the KLX purchase now? Since we are blessed with all kinds of nice Sierra back roads, fire roads and trails here in Norcal I thought it was foolish not to be taking advantage of the riding opportunities before incipient decrepitude renders me unable to do so.

The KLX is much lighter and more compact than my main scoot, a 650 Wee-Strom. The 'Strom is more of an "adventure tourer" and has taken me to AK twice in considerable comfort, but at almost 500 lbs really isn't suited for rougher off-road surfaces. The downside of the KLX is the utter lack of power, but I intend to just putter around up in the hills anyway.

It's got a full FMF exhaust including "power bomb" header but that will almost certainly come off soon and be replaced by the OEM setup. (I hate loud exhaust.) Fortunately the seller had all the OEM stuff including jets so it will be a simple transition. I may have to adjust it a little on the leaner side of factory setting, though, since most of my riding will be above 5000'. If anyone has appropriate jetting suggestions I would welcome them.

Anyhoo, I will be hanging around this forum on a regular basis and hope to glean a trove of priceless wisdom about the care, feeding and use of this fine machine.

 

Welcome aboard. What part of Norcal are you from?

 

Right next door...Placerville.

 

Welcome to KF.
At 5,000 ft and going back to stock pipe with an airbox lid and snorkel, may as well try stock jetting with a #35 pilot and #118 main jet. Uncover the fuel screw so that can be adjusted for elevation.

What FMF do you have? The Q4 with quiet core is about the quietest aftermarket available. Stock pipe with airbox lid and snorkel almost quiets it down to a sewing machine.

 

Thanks for the jetting info. I'm pretty sure the fuel screw is exposed because it came with a complete Dynojet kit apparently installed when the FMF was put on.

It's a Q4 but "quietest" is a relative thing. What does the quiet core look like? A sewing machine sound is pretty much what I'm aiming for. I'll have to check to see if the PO removed the snorkel. I haven't really dug into the thing's innards yet. Trip to DMV for title transfer this PM, then the exploration begins.

 

You're going to lose a bit of power taking it back to stock, but it will be quiet.

The quiet cores are in this link.
Products - MX - FMF Racing

If you want to keep the dynojet jetting, you may want to give them a call to see what they recommend.

 

Cool, lots of places to ride up there.

Let me know if you decide to sell the Power Bomb.

Can someone refresh my memory, Power Bomb or Mega Bomb for more top end?

 

So I pulled off the seat to inspect and clean the air filter and notice that the top of the airbox has a rectangular (with rounded corners) large hole which would seem to be from the factory, and two 1 1/2" holes apparently drilled by the PO. I'm not sure what the infamous snorkel is supposed to look like, but there ain't nothin' remotely resembling one on this airbox, just those three holes on top. Thus it seems as if the breathing apparatus has been opened up somewhat. Accordingly I'm beginning to think that it's possible the OEM jetting (with factory pipe/muffler) may be adequate for higher altitudes since most bikes come pretty lean from the factory to satisfy EPA and the modified airbox will lean it out even more. Since I don't know how restrictive the snorkel was, though, I can't really estimate what its removal means with respect to jetting.

The OEM main jet which the PO changed out was in the Dynojet kit he gave me. It is a 118, and was apparently replaced with a 128 because that's the one missing from the kit's content list. A needle jet with clip is also in the box, but it has no size marking. I assume it's the OEM since the Dynojet kit says the needle it provides is 228. Was the slide spring changed? Who knows? That's the trouble when you get something previously fiddled with.

(BTW, the Dynojet kit -- which says it is for the 2009 KLX250S -- contains main jets sized from 112 to 132! How many stages of tuning is that?)

 

Here's a picture of the snorkel. The thinner one is the stock snorkel, the wider one is the KDX snorkel, which lets in more air. Some people will remove the snorkel and/or air box lid to let more air in. Personally, I don't like the snorkel out as the bike is louder and vibrates more.

 

Find a parts fiche on line and you'll see what the snorkel looks like. The lack of snorkel and the holes will produce more intake noise and tend to make it leaner. Be careful going full stock 118 main with this open airbox.

Here's a snorkel
Kawasaki KLX250SF Airbox Snorkel KLX 250SF 2009 Mint 5 | eBay

The stock needle doesn't have a clip. I wonder if that's a KLX300 N1TC needle?

The slide spring, if changed, should improve throttle response. I doubt this will make a big difference for you trying to go back to stock.