To all you Kawasaki dual sport experts out there:

I am the proud owner of a 2006 KLX 250S. I'm a 40 year old married with kids ex dirt biker that was looking to get back into riding bit did not want to trailer a bike all over the east coast to find a place to ride off road.

My complaint is primarily with slow throttle response, long throw of the throttle itself, and of course a little more power. I am trying to do this on a tight budget. Have read through many of the threads in this forum and seem to have come up with the following:

1) Dynojet kit (use KLX 300 kit?, what standard settings should I start with?)
2) Remove airbox lid, airbox wire mesh, install aftermarket filter (recommendation of best after market filter?)
3) Install short throw throttle (need to know where to find a part that will fit the bike without modification to the carb)
4) Drill 1/2 hole into stock silencer (how far do I have to drill inside, the whole length of the silencer?)
5) Plug and/or re-route emissions tubes from crankcase and air box (need specific recommendation on this one)
6) Re-route carb vent lines away from bottom of bike and put small filter on the end of the lines
7) Is an iridium plug worth the money over a stock plug?

Feedback from experienced riders who have done these mods before is much apreciated. Also a good recommendation on where to get these parts online and part numbers would be very helpful

Thanks,

Rob

 

Probably the most important mod for faster throttle response is to drill the slide vent hole. This is inside the carburetor and is the hole beside where the needle sits. Drill that to 7/64ths. That hole controls the vacuum which raises the needle which allows fuel to flow. Making it a little larger provides faster response, but you don't want it too large, otherwise it won't drop back down to idle very quickly when you let off the throttle. 7/64ths is the size most use.

But while you are in there, jet the carb as you said. Dynojet will work. I did not use it, though, and just ordered a #125 jet and N1TC needle, clip, and collar. My setup has the clip on the 2nd ring from the top of the needle. Also, you will want to remove the cap off the fuel mixture screw so you can adjust it. After you remove the cap, tight the screw until it just seats, then back it out the required amount - mine is at 2.5 turns. These work OK for me but you will find that what works for one is not necessarily optimal for another bike / location. YYY.GUY on this forum was collecting everyone's settings and putting them in a spreadsheet somewhere - maybe he can point you to that so that you have an idea of what works for various elevations.

There is good coverage of all these mods referenced from the moderator's Welcome thread which should be sticky at the top of this forum section. Also, the HMF slip-on pipe web site has a forum where they also do a very good job of describing most of these mods. They retained and shimmed the stock needle, though instead of using a Dynojet or N1TC adjustable needle, but the procedure is the same regardless.

By drilling the stock pipe, and just ordering a new needle and jets and perhaps the KDX200 hi flow snorkel, you can do this first round of mods for only around $50 or $60. And you will notice a significant difference in both throttle response and power. The bike is so plugged up from the factory that just rejetting and opening things up a little really helps it out a lot.

Good luck!

 

The 13 tooth c/s is the first mod I did very well worth the 15-20 bucks.

 

And you can uncork your exhaust for free by drilling out the first (or even second) baffles (drill right through the exit hole)...
This is considered one of the "free" mods, along with the smog system removal, drilling out the crank breather, pilot screw adjustment, airbox modifications (can be free).

 

Welcome Rob, gearing and exhaust and jetting will produce the best results, but don't go by what I say, I'm 40 something and have kids and just getting back into riding after,.....well let's just say the last dirt type bike I had, Ronald Reagan was president Again Welcome. Oh and have your wife or gf check out the XT 225, my wife loves her new bike. Check out the latest deej report.

 

simplest easiest and quickest stuff... (my current setup)
13 tooth sprocket is a must
kdx200 snorkel
drilled baffles
rejet

now i havent gotten around to a diff filter but id recommend a uni for better airflow. make sure you get the uni prior to jetting or you may end up lean if ya add the different filter after jetting.
the emissions stuff wont make a diff in performance so its not really worth the trouble. giving the line from your crankcase to the airbox less restriction will make a diff... that can be done one of two ways... drilling the entry into the airbox to 3/8's or running the line to a filter (located up high) and plugging the old entry to the airbox.
just remembered... if you pull the mesh located behind the airfilter in your airbox your taking a big gamble... that screen is protection from a backfire turning your bike into a molotov c0cktail.... def not something id recommend.....

 

Question? If you drill out the baffle do you have to rejet or will it still run fine?

 

the klx comes ridiculously lean right from the factory any mod done to allow for more air into/out of the engine will make the condition even worse... so in short.. yes[8D]

p.s. as an afterthought any mods done to the airflow should be done prior to the jetting... filter... crankcase breather... snorkel... baffles etc. as any of these small simple mods may throw the jetting off once its been done.

 

I too saw this in the HMF slip-on thread. They said removing it was good for Half a horsepower but also warned about the backfire problem. Then in the very next line they recommened getting a K&N filter. I got the impression that with a K&N it wasnt a concern unlike the Uni Foam filter. I'm going with a K&N myself...



LV

 

K&N are known for the filter being unsuitable for very dusty conditions as the openings in the filter material may be to large and let some smaller particles through into the engine.