Hey everyone! New to the forum and a new owner of an 09 klx250s Being completely new to this bike and the whole dual sport culture I have a few questions. I had posted this over on thumpertalk but this site seems like it suites my topic better

"As the title suggests I just purchased a 2009 Klx250s and have a few questions for current or previous owners of this bike. One being what are your maintinance routines/schedules like? this is my first dual-sport so I'm kinda lost there. Secondly what modifications, whether aftermarket or do it yourself, do you suggest I do to get this bike running like a champ? I love doing my own work so if anyone has any little tricks or tips please share. Also if anyone has any suggestions or anything to add that my questions don't cover feel free to let me know! Thanks!"

I'm really interested in doing some of the free mods, I've gone through tons of pages, but there's just so much information out there its making my head hurt I'm the kind of guy where if something can be made better, I won't be happy until its there. I already know I want to take the snorkel out of the air box, but as far as intake what other mods can I do? are there any free mods I can do on the exhaust system? And when all thats said and done what settings/mods should be done to my carb? I'm really sorry about all the questions, I know the answers are out there, I just want to make sure I get it right. If someone could go right out and say this is what needs to be done you'd be my hero

 

Oh boy, you are like me, I'll end up dumping so much money on accesories it won't even be funny. I believe you can drill a larger baffle out of the exhaust to make it flow better, but in all honesty you are going to want a slip on, they are MUCH lighter. For the carb you need to do the jet kit if you remove the snorkel, fairly simple, take your time and remember where and how it all goes together for future purposes. Put a uni or k&n filter in it, change the front sprocket from a 14 tooth to a 13 tooth (sometimes hard to get off, put bike on center stand, step on brake, and use a breaker bar) uhhhhh that's it I think...

 

Having lived in AZ, I would stick with a good foam oiled filter. Dust abounds there, not good for engines, you should see my old EX motor that sucked some desert dust through a freshly cleaned and oiled(or whatever their stuff is)K&N. That trip ended at home fortunately, but that was as far as she went. No such problems with foam, if you take care of it, cheap insurance. Wish I never switched to a K&N, but it worked so well in my truck...oh yeah 8 cylinders to abuse, as opposed to 1 or 2.
Just saying.
Sucking dirt, really sucks.

 

Yeah...I have every intention of going bankrupt getting this bike where I want it haha. I'm currently looking into the dynojet stage 1 and 2 kit, does it come with a variety of jet sizes or a predetermined size for each? If I remove the snorkel and slip-on whats a good starting place for jet sizes? Also i read about drilling out the air/fuel screw and the hole in the throttle slide, is that something I should do?

I planned on switching the front to a 13 and the rear to a 45 so thats one thing I'm not completely lost on

Trust me...I know all about dirt ruining nice things...unfortunately haha. I plan on keeping the foam filter for sure, about how often did you change your oil and clean your filter while living here?

 

Well I was fine for about 10K, until I ran a K&N for about 3000 miles(checked, cleaned, regunked(technical term), and reinstalled(correctly)). I also ran through some dust storms while returning from LA, that was the killer. It just ate the rings away after that and I had a smoker with very little power until I got home. One cylinder seemed to suck a bit more than the other, but it wasn't pretty. It was amazing that it ran that far, after seeing how worn the combustion chamber got all of a sudden, maybe it was it's last dying gift to me, to return me home one last time.
Ah jeez, now I'm tearing up. Haha. Still got that bike, newer engine, FOAM filter.

 

Ok so for sure go with a uni filter, it is foam I believe. I went with the stage 2, not much of a difference really. It comes with an assortment of jetting sizes. I didn't do the slip on yet so I went with the 124 jet, drilled out the plug for the fuel screw and turned it to 2 3/4 out (too rich for me gotta get around to adjusting it). I would say with the snorkel removed and the slip on go with a 128 main. I don't recall the bit size but drill out the starter jet for easier starting. With the dynojet kit with the new needle and shorter spring you won't need to drill into the slide. I'm no expert by any means, but I've had the bike for 3 months and been reading about it for about 8 months and am a mechanic by hobby :P Best of luck! hopefully TNC or Deej will pop over here and clear up anything I missed.

 

Okay, sorry it took so long to get back here, so had the bike for about 3 weeks now and am loving it. Definitely lacking a little in the power department but this weekend if all the stuff I've ordered arrives I'll have a KLX300 muffler, Uni air filter and a Dynojet kit ready to go. Plan on removing the airbox snorkel and the butt plug in the exhaust. So with that all being said does a 128 main as Rockabill said and about 2 1/2 turns out on the fuel screw sound about right at 2500 ft above sea level? Leave the pilot jet as is?

 

Stock pilot is fine even on a total stage 2 mod which you won't be at.

 

Start off with Marcelino Cam mods, you will find them at the top of the sticky posts. Free mod that will give you grunt where you need it. Open up the airbox, put in a 20 buck uni filter, but plug, rejet and you good to go. Anything else you buy, besides a big bore kit is just window dressing.

 

I disagree, exhaust that sheds 6 or 7 lbs is nice, and increases flow. The 13 tooth front sprocket also does woders for more pep on te street and in the dirt