Long term KLX250S review

Discussion in 'Thumpers' started by bmwhd, Dec 2, 2005.

  1. Nobiman

    Nobiman Orange... the color of insanity.

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    Thats good advice Backwoods, I'd go with it.

    Get all of the parts gathered first, then do the jetting, air box snorkle, de-smog and exhaust all at the same time. FWIW, I had an extra long 1/2" x 12" drill bit and drilled about 8" into the stock silencer while we were waiting for the Muzzy to arrive. It made very very little difference in sound or performance IMO. That stock silencer really needs to go as soon as you can afford it, Then all of your other mods will be used to thier full potential when the motor can get rid of all the exhaust gases it makes without straining at the very restrictive silencer. Until then, have a blast on your new bike dude!

    Randy.
  2. Nobiman

    Nobiman Orange... the color of insanity.

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    Hey Backwoods, all of these mods can be done in your garage with simple hand tools. Take the time to do some searchs 'cause we've all tried to document these mods with pictures so everyone ekse can "see" whats being done.

    The air box drill mod really has very little to do with the snorkle mod. The snorkle mod increases the influx of air into the motor, which is why you also need to rejet too, more air means more fuel or you will create the lean condition that NoBrakes described above.

    The airbox drill mod increases the size of the hole for the engine vent line, which allows the engine to keep from building as much pressure inside, which in turn usually allows for a more responsive engine. Any one of these mods will make little difference but all of them together will make a very noticable difference in performance. So get all 'yer ducks in order and jump into that baby! YOU CAN DO IT!:lol3

    Randy.
  3. Nobiman

    Nobiman Orange... the color of insanity.

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    Can ya post a picture of this condition? I have not heard this one before!:huh

    Randy.
  4. nobrakes

    nobrakes Long timer

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    Backwoods - listen to Nobiman, that's it exactly, he hit the nail right smack on the head! :deal
  5. MaverickAus

    MaverickAus Long timer

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    Just to add to what Brian said, watch ebay australia ( www.ebay.com.au ) for the kits and the dealers no longer supply them with the bikes. Also I don't think Kawasaki Aus is selling the kits anymore.

    cheers

    Garry

    P.S. my kit is not for sale so don't ask :p
  6. nobrakes

    nobrakes Long timer

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    I can vouch for Mav on that - I already tried to buy his and he would have none of that nonsense. :D
  7. backwoods

    backwoods Field & Stream

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    Great stuff guys. I guess I'll see about an exhaust system first but I didn't want something real loud. I found a complete system by Big Gun made specifically for the "new" KLX250s. Has anyone put this one on thier bike and how does it work.

    backwoods
  8. nobrakes

    nobrakes Long timer

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    If you're concerned about that, just do the 1/2" drill mod in the stock pipe for now in addition to the usually airbox and carburetor mods. I ran my bike for a while like that before getting the Muzzy and while I think I saw a slight improvement when I installed the Muzzy, I got most of the improvements from the carburetor and airbox mods. That was until I installed the 300cc cylinder and piston, at least. :evil

    Another option is to get a stock KLX300 pipe - you can find these economically from folks that have them lying around after replacing theirs with aftermarket brands. The KLX300 exhaust is an improvement in both performance and sound over the stock KLX250S pipe. And once you have a KLX300 head-pipe, that opens the door to the aftermarket pipe slip-on options which are generally cheaper than the full systems.
  9. KLX X 2

    KLX X 2 Randy

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    I have the big gun on my bike. I had the 13 tooth sprocket, big gun, KLX Filter & re jet done at my dealer all at the same time. My wife's Klx is stock and jumping from one to another is a shock. MINE is just way faster.

    I have my silencer out of my "BIG gun " right now and it is LOUD. Much More quiet with it in but a bit less power. I tend to wear ear plugs to keep down the wind noise when i ride anyway.

    Randy
  10. backwoods

    backwoods Field & Stream

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    O.K, here's what I want to do.
    I want to obtain a KLX300 header pipe and keep the stock cannister with the first baffle drilled out. I'm not concerned with weight.
    I want to install a high flow snorkel(92-99 KDX200).
    I want to install a #125 main jet.
    I want to remove the needle and put it on the 2nd slot.

    Do I need to order the dyno jet kit?

    Can anyone confirm that this would make a noticable diffrence and will it work. I know I'm missing a few of the mods but this is what I want if it will work. If I had to order the exhaust system I would want the staintune.

    Thanks again, all replies welcome.
    backwoods
  11. bryantjt

    bryantjt Long timer

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    The 300 header will not match up with the 250 cannister, pipe flange diameter and pipe lengths are wrong. Here is some info from a member over on the Kawi forums regarding something similar to what you are wanting to do:

    Honestly, with the spark-arrestor removed, I don't think there is much of a performance difference between it and an after-market pipe. There is a few things that I do like about the KLX300 pipe. One is that it looks stock. Another is you can make it as quiet as stock if you put the spark-arrestor on. I made a little plate in place of the spark-arrestor so I could tailor the sound to my liking. The 300 pipe does remove some weight, I think it was like 3 pounds. It gets rid of the stupid catalytic converter. If you run it with the spark-arrestor, you won't need to jet for it. But if you remove it, you will need to re-jet. Right now, I have a 125 main jet. My brother is using a 122.5 jet with his.

    As far as how does it sound? With the spark-arrestor out, it sounds like a typical single-cylinder does with loud exhaust. I attached a couple sound files. The bike without the spark-arrestor is much louder in person than the one with the plate and 3/4" hole. Hopefully it will give you the gist of what is sounds like. It does not sound like the same bike. An after-market pipe will probably have a nicer tone to it than one of these mufflers, but I am happy for now. I would rather spend $400 on the 300cc kit or a pumper carb, but that's just me.




    Also here are some pics of my bike with the 300 full exhaust and a short video. I have not rejetted I just wanted to see how it sounded and then put the stock exhaust back on.


    [​IMG]

    [​IMG]

    Video: http://video.tinypic.com/player.php?v=1569vlw
  12. backwoods

    backwoods Field & Stream

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    I appreciate the info but I'm confused. I thought I read the stock header diameter was smaller than a KLX300 header pipe and some of the others had replaced the stock header pipe with a KLX300 or one from fourstroke.com and then drilled out the stock cannister 1 baffle and connected the two together. I guess with this thread being so long it takes me two nights to read it all and I forget what I read.

    I like my bike stock for the most part. I have no concerns about weight or a bigger fuel tank or a big bore kit. I just want to reduce some of the restrictions due to EPA and find some get up and go that we all know is in there but restricted because of emissions. That thread you sent says I don't have to even rejet now. I know your being helpful but I'm confused about it all now.

    backwoods
  13. MaverickAus

    MaverickAus Long timer

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    I think you will find the ones that used a KLX300 header also used a 300 muffler too. The 300 header pipe will not fit the 250 muffler from what I have read, its too long. I believe Staintune make a header for the 250 that fits the muffler, but I would email them first
    Cheers
    Garry
  14. Nobiman

    Nobiman Orange... the color of insanity.

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    Backwoods, it was suggested to you to try and pick up a stock 300 header from someone who upgraded to an after market system so that you could buy just the slip-on from Muzzy, Staintune or Big Gun in order to save money. I personally dont see how this many changes can be made without re-jetting, buts thats JMO.

    Here is the difference between the 300 header pipe diameter and the 250. I was sent the wrong pipe from Muzzy, it was a slip-on for the 300 (top part in pic) which will not fit the 250 header (bottom part) so you need either
    the stock 300 header, & the slip-on to match or the full KLX 300 system.
  15. backwoods

    backwoods Field & Stream

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    All right, I'm placing the order tomorrow. I have a couple of other questions?

    Can I leave the pilot jet stock?

    Can I leave the smog crap on, and not do the crank vent mod?

    I will be ordering:

    125 main jet
    2.5 turns out on pilot screw
    big gun exhaust system
    snorkel (part# 14073-1577)
    UNI filter
    N1TC(needle,circlip & collar)with clip two down from the top
    slide port drilled to 7/64ths


    I'm hoping this will bring the bike alive! Once again all replies and opinions appreciated. If something here is wrong please advise. If it works I'm sailing!

    Backwoods
  16. nobrakes

    nobrakes Long timer

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    No - you cannot mix and match KLX250S and KLX300 exhaust parts. You need to replace both the head pipe and the silencer, not just one of them. What I said was that once you have a full KLX300 pipe, you can _then_ use an aftermarket silencer on it, since aftermarket silencers don't work with the KLX250S head pipe, but they do with the KLX300 head pipe. Just like you can't use a KLX300 silencer on the KLX250S head pipe, you cannot use the KLX250S silencer on the KLX300 head pipe. While the full exhaust system can be replaced with KLX300 parts, individual pieces cannot.

    But if you buy, say, a Muzzy full system which includes the head pipe, mid pipe, and silencer, then you are done - you have everything you need, exhaust-wise.

    And regarding the needle - note that I gave a whole new needle part. The stock needle on the KLX250S is not adjustable - it is fixed. You need to _replace_ it with the part number I provided, not just remove it and change the clip position. There is no clip to adjust on the stock needle. Don't forget to also order the collar and the clip which I also gave part numbers for. If you buy all these parts individually, you do not need the dynojet kit - that would be redundent. I got these parts from BikeBandit.com. RonAyers.com is also a good source.
  17. backwoods

    backwoods Field & Stream

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    That's great news nobrakes, my head is in the game again. I have all the part #'s you provided. I don't know whether to buy the big gun exhaust or muzzy. I spoke to both Muzzy & Big Gun today and muzzy said I could keep the spark arrest and the insert in to reduce noise. Would this reduce performance?. Big Gun is a $100 more for some reason.

    What would the muzzy sound like with insert installed & no spark arrest?

    Can I leave the stock pilot jet?

    Can I get away without the crank vent mod and just do the 7/64th slide drill?

    Backwoods
  18. Nobiman

    Nobiman Orange... the color of insanity.

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    Stock pilot will be fine. We noticed little, if any difference in sound with the quiet core and spark arrester installed. May be our ears are not tuned for decibels!:lol3

    Randy.
  19. nobrakes

    nobrakes Long timer

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    As Nobiman mentioned, stock pilot is fine.

    Regarding Big Gun vs Muzzy - you really can't go wrong with either one, IMO. Muzzy owners love theirs and Big Gun owners love theirs. HOWEVER, and this is based purely on rumor, inuendo, and hearsay from other internet reports, the Big Gun may be slightly louder than the Muzzy. But take that for what it is, I have no direct knowledge on that except from what I've read elsewhere. To the best of my knowledge, no one has used a dB meter to measure the outputs side by side and report the results. So if everything else is equal, but quieter is more important to you, then the Muzzy _might_ have a slight advantage. If you want it quickly, you'll probably have better luck with the Big Gun as the Muzzy seems to be back ordered again.

    I have the Muzzy with spark arrestor and quiet insert. It sounds good to me. Here's a video clip I made mainly for the audio that compares the stock exhaust with that of the Muzzy w/spark arrestor + quiet insert:

    video ...

    It was made using the same camera and microphone in the same location on seperate days so it should give a pretty good comparison of the sound levels. Without the quiet insert, the Muzzy cracks pretty good when you lay on the throttle. The quiet insert softens that down quite a bit. I doubt the spark arrestor makes much difference.

    Also, you can pass on the crankcase vent mod. I'd recommend doing the 7/64th slide drilling though - that gives you faster throttle response and is one of the upgrades that I personally liked a lot!

    EDIT: video link no longer works
  20. KLX X 2

    KLX X 2 Randy

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    Here is a photo of the "Big Gun" on my KLX with flush signals. Got a new tail light on order so I can move the licence plate up and remove that chuck of black plastic on the end of my back fender.

    Randy:clap