Hello, new to the forum as I just purchased a 2013 KLX 250s which had 1,750 miles of dirt road use on it two months ago. I really like this bike and glad to be back on the dirt after a 25 year hiatus. Very apparent to me that the stock exhaust on these bikes greatly restrict the fun potential. So after reading posts into the wee hours of the night the last several days I've decided to go with a slip on exhaust and rejet the carb with a Dyno Jet kit. I'm hoping for help with which slip on do you recommend? Any particulars I need to be aware of in going with the Dyno Jet for a 2013 and where do I get it? And will I have to rejet again if I start playing with the air box and snorkle later? Many thanks in advance for any help!

 

Houstons, welcome to KF.

If you're looking for a quieter aftermarket slip-on, the FMF Q4 with quiet core is the quietest out there that still offers a good performance boost. If you're looking for loud, there's many options.

 

Cheaper slipons, under $200 - DG's, Delkevic(https://images.delkevic.net/product6673_3.jpg - http://www.delkevic.us/index.php?rou...29&SKU=KIT04CF) NOTE: these two choices will not mate to a performance header(FMF, FSW, etc) , so if a performance header is a possibility in the future, you'll have to spend the money on a FMF slipon for now..

Use a DJ2152 or a DJ2206 kit. Running without the lid is a radical mod that requires a completely different carb setup than running with snorkel or with lid sans snorkel. Going from stock header to performance header also requires a different carb setup.

If you want to run lidless, see my "DGR" link below for the correct recipe. You'll get nearly 5 more HP and over 4 lb ft TRQ increase - this increase gives you a totally "new" bike.

Also, if you want the performance of running lidless, I'd get the DJ2206 kit, then call DJ and order the correct main jet for your altitude(which you'll be doing anyway), AND the slide spring that comes in the DJ2152 kit. Use the spring instead of drilling the slide lift hole.

 

Klxster, sold!
No plans of adding a header later (why would I after seeing your wheelie video). So from what I'm gathering from your "DRG" link by adding an additional mod of running "lidless", with a slip on and get the DJ2125 kit (I'm below 5,000 sea level) and purchasing the spring from the DJ2125 kit, your charts will apply to my rig? Amazing. Two questions:
1). Can you define lidless.
2). limited carb experience (rebuilt my '47 ****** single barrel a couple of years ago), I presume most of your rejet recipe will make more sense once I receive the kit?

Thanks a ton!!

 

Lidless means removing the airbox lid and putting it on a shelf - or better yet, in the attic, behind the old boxes nobody has thought about for several decades..

DJ2152 kit + ordering the correct main jet for your altitude.(DJ140 for near sea level)
OR
DJ2206 kit + ordering main jet and the slide spring from the DJ2152 kit.

As I said, the 2206 kit has a needle(that DJ won't sell you separate) that is designed for lidless running. While I do not have data/charts to show with this combo, if I had your bike, this is the way I'd go - but I am adventurous and if you are not, then just use my DJ2152 kit + DJ140/2N recipe.

If you are near sea level, you should also look into ordering the #40 pilot jet (Kawa # 92064-1108) .. This will insure that you can adjust out any decel popping, which usually crops up after performance modding the exhaust and carb..

If you want the performance, you do the carb.. If you screw it up, you'll know immediately.. best to do it right the first time.. Here is my link to troubleshooting - it'll give you an idea of what all you can mess up while rejetting..lol https://www.kawasakiforums.com/forum...s-fixes-43146/

 

Wow, blown away by the detail and amount of information. And I just bought this bike for my 17 year old to ride around town. I hopeful the DJ kits come with good instructions?

Any preference on slip on's, you mentioned DG's are cheaper which isn't top priority as much as quality/longevity. I want somewhat loud (safer in the trails) but not it's the hooligan neighbor loud.

Doesn't sound like I can go wrong with ordering both the DJ2206 & the DJ2152 to get the slide spring option. What am I missing, meaning why would I not go with the slide spring option other than the additional cost of another kit? Both are equal in amount of work jetting the carb, agreed? I guess my last question would be other than being adventurous what are the disadvantages of this verses no slide spring? and oh, does running the snorkel affect any of this?

Thanks again!! you have saved me an abominate amount of research time!

 

Ah, somehow you are not understanding me..

You choose either the 2206 or the 2152 kit - never both. If you are going to run lidless, you will be calling DJ for a main jet, a few more needle washers(because they have a habit of running off.) and, if you choose the 2206 option, a slide spring( the one that comes in the 2152 kit) .

The 2206 instructions will have you drill out your slide lift hole with the supplied bit - which is perfectly fine, but is a permanent mod on an expensive part. I suggest instead of drilling the lift hole, you use the lighter spring that comes in the 2152 kit, and that requires you to call DJ, tell them you have a 2152 kit(a lie), lost the spring, and need another one, as well as a few more needle washers and a DJ140 main jet(if you are near sea level)..

ALL the slipons will be loud. Some more than others. All are good quality as there are no posts in here otherwise as best I can remember/know.. DG-R, 2Bros, PC4 - Louder by most counts. DG-O, Q4, softer by most counts. Delkevic is unknown as only one or a few members are running it with no posts of sound characteristics. I like the Delkevic because it has a properly designed "tail pipe" that directs exhaust away from the turn signal.. My PC4 and DGR melt my turn signals!

If you want to run with the airbox lid on the bike, you will be following the instructions for the DJ kit and using the supplied parts. With snorkel-stage 1, without Snorkel, stage 2.

So, yes, running the snorkel affects everything. Running the lid w/o snorkel affects everything. You decide how you are going to configure the airbox, then you rejet for the configuration you've decided to run. If you want max power, you run lidless with my setup recipe.

 

I am now.

Thanks again, I will certainly keep you posted.

Funny thing, I noticed with just about all the slip on's I've seen images/videos of that the turn signals looked vulnerable. I like the sound in the attention to detail of the Dekevlic company as well, and really like the look of their carbon silencers with the black and white plastic of my KLX.

Thanks once again!!

 

You're welcome.
Looking forward to your results!

 

Update; Just spoke with Dan at DJ (who was great and patient with my deep interrogations). He was adamant about steering me away from going with the 2206 kit (sounds like I wasn't the first to request this recipe) and keep me with the 2152 kit. He also said I do not want to go with the 140 main jet and run lidless, stating I would gain greater improvement with lid but without snorkel using the 128 main jet? However, as a new disciple of your recipes Klxster I added the 140 MJ as well. I will say though that in the vast wilderness trails of northern Michigan where we do the majority of our riding water crossings are part of real life here in the great lakes region of the planet. I was also told the #40 pilot jet was not needed.

Also, I've ordered a very sexy looking 14" oval stubby carbon slip on from Delkevic I'm pretty excited about. You don't see these silencers everywhere and I really appreciate companies with this attention to design detail (thank you Klxster). I am having trouble locating someone who has the #40 pilot jet in stock, so any insight of a place who stocks this would be appreciated, as I am going lidless. I have just about everything I need to be dangerous at this point and don't want this pilot jet to hold me up.
This bike is for my 17 year old, but I'm now convinced I will find another KLX 250s for myself which means, I will eventually be doing the 2206 kit recipe to one up my boy.

Lastly, what is a MCM modification?

Many, many thanks again!