Don't run sustained high RPM with that 132 main as the AFR will be lean (if lidless).. Lidless running with your setup will require a DJ 140 main jet..

So, on second thought, perhaps you should consider the 132 with the snorkel for the trip..

 

Thank you for the recommendation. My riding buddy bailed so no trip. However I think the elevations are fairly typical for rides around here so will try the 132 and see how it works.

 

New 07 KLX250S owner here. I'm just about to order a FMF Q4 and jet kit. What do you mean by lidless above?

 

Q4(w/o quiet tip) + stock header + airbox lid removed

For maximum power, the above setup will require a DynoJet 2152 kit, and a call to DJ (or your local tuner shop) for a DJ140 main jet. Installed as per intructions except with the DJ140 main and needle clip set to 2nd notch down (2N). Results are 21 to 22hp..

Add MCM to the above for another boost in power levels.

Add a PowerBomb or Megabomb header to (above setup + MCM), reset carb with DJ144/1N , and get another big boost in power - in this case, power that pulls hard to 10,500 rpm..!

Edit 12/2016: Latest dyno testing indicates Slipon+stock header+lidless airbox requires DJ140, clip at 2N or 1N, and stock slide spring.

 

I need my reading glasses. I read that as "IDLE-LESS" not "lid-less" lol.

Is the KDX200 snorkel a good second option if we want to retain the lid (for water crossings, ect)?

 

I don't have data as I have not dyno'd carb setups with snorkels..

Given the design and structure of the KLX250s' area in question, I don't understand the scenario whereby a KLX snorkel will allow the bike to continue running when lidless wouldn't..

 

[QUOTE=Klxster;528543]Q4(w/o quiet tip) + stock header + airbox lid removed

For maximum power, the above setup will require a DynoJet 2152 kit, and a call to DJ (or your local tuner shop) for a DJ140 main jet. Installed as per intructions except with the DJ140 main and needle clip set to 2nd notch down (2N). Results are 21 to 22hp..

Hi Klxster

Just purchased a 2007 and bought the 2152 kit and DJ140 main. This will be a woods bike. I have a harley for the road.

I have stock exhaust and live close to sea level. Will the above set up work for my bike? Should I expand the opening at the rear of the exhaust to allow freer flow? Is a slipon going to give me much more? I would like to eventually like to do the MCM mod, but will probably have a shop do it for me over the winter as it looks intimidating.

Thx Kevin

 

[QUOTE=kshanks5;528848]Hey Kevin.. You'll need a performance slip-on in order for DJ140/2N lidless to work correctly.. The DG's and Delkevics are inexpensive but do not allow for a future addition of a performance header.. I like this Delkevic, it has a O2 bung too ! - Stubby 14" Stainless Steel Oval Muffler to fit KLX250 (2009-2014)

If, for now, you stay with the stock exhaust, just install the 2152 kit as per instructions for stage 2 (pulling the snorkel, not the lid) but use the included 132 main jet..

The MCM is not hard, it just requires "mechanic talent" IMO.. There is no room for guessing and cutting corners..

Now in case you don't know what to do, I can help you a little .. Once you experience DJ140/2N, lidless, with slipon, you will be "hooked" - You'll be moving up your MCM timeline: When the MCM is done, you'll be completely out of control - enjoying what you have, but you'll know there is a great deal more by adding a header and resetting to DJ144/1N.. If you have purchased a slipon that will not accept the larger O.D. of a performance header (I.E. a DG or Delkevic), you are screwed..

This is why I would advise a FMF Q4 or PC4 as your slipon - I know how much it sux's to spend that much more, but you only have to do it once with either of those two..

 

If you want more options, just speak up..

Know that with a $475 FMF system(Megabomb+PC4) , a DJ144 main jet, and one long Saturday afternoon (for installation of the above as well as the MCM) - your bike goes from Zero to Hero. And, your DONE spending money and time on engine mods FOREVER !!

 

There's a sale on the Big Gun system for your/our bikes $484 - Big Gun EVO R Exhaust System - Motorcycle Superstore

That Big Gun system on ebay $443 - Big Gun EVO Full Exhaust Pipe Muffler Kawasaki KLX300 00 01 02 03 04 05 KLX 300 | eBay

FMF megabomb system $479 - 042246 & 042251 FMF Powercore 4 Muffler & Mega Bomb Header - 2006 Kawasaki KLX250S

While I don't know how loud the Big Gun system is - I do have a Big Gun system on a Husaberg and it is LOUD - I do know the PC4+Megabomb is pretty quiet when ridden with care..