99-02 KX125 OK for enduro use?

Discussion in '2 smokers' started by tHEtREV, Dec 7, 2016.

  1. tHEtREV

    tHEtREV Encouragement award recipient. tEAM iDIOT.

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    After a bike shuffle I decided I want a 125 two stroke to do a few races on and take to the motocross park next year.

    I was originally thinking I'd just get a KDX200 (I just have a thing for them), but decided I have a KTM 525 so I may as well get something a lot lighter and slimmer, and thought a 2000 era 125 MX would probably be a better starting point anyway.

    Now running from memory, the last major changes for big the four 125's was 03 for the KX, 04 for the CR, 05 for the RM and 06 for the YZ (I could be a year or two out on any or all of those), and I had my heart set on a KX, and I thought I might have the best chance to snag one being the oldest.

    But of course I have a small budget, and the only bikes that seem to be popping up within that budget are pre 03 KX's.

    I know they were criticised for being gutless in standard form, and 03 was supposedly slimmer, but are they that much worse than the 03, or would I probably not notice a difference?

    So should I keep holding out for an 03 or newer, or just go for a tidy 02, or any other suggestions on what I could consider?

    I'll also be keeping an eye out for any of the others, and I have been tempted by a few 250 4 strokes, just because you can get a newer one cheaper (but I am well aware that they will probably need a rebuild or go bang at the most inappropriate time), Huskys are on the list but rare, and KTM's are going for stupid money.
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  2. gots_a_sol

    gots_a_sol Long timer

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    I have an 02 KX that I bought for a beater/back up bike this summer. I was looking for a blown up bike to drop a kdx mill in to, but this bike was in pretty nice shape for not much more money than what folks wanted for dead bikes.

    The engine is a light switch that goes from blaaaahhhhhhhh to OMGIWANNAGOFAST in a millisecond. Fun early in the day, not so much at the end of it.

    The suspension sucks. Depending on year the forks are an easy fix with some parts swapping (06/09 YZ SSS forks fit 02+ kx's, at least they did on mine. 99-01 uses different triples, but I think they swap out with 02+). I'm still working on the shock. Being as light as these bikes are, they are a bit skittish.

    Most parts are still available easily which is a big plus over the older euro bikes, although they do make much better woods/enduro bikes.

    I've ridden the KX up to 70 miles in a day and while it did it, it definitely wasn't the best/most comfortable tool for that, especially the stupid hard stuff we were riding.

    Pretty sure all 125's will have close ratios transmissions which is dookey for road use. I have both my KX and Husky geared a little closer to hard technical/single track and they'll cruise at 35 mph comfortably. They'll go quite a bit faster, but you get up in to the power band and they starts screaming. A bit of an attention getter.


    Recap: It is a lot of fun to wail on a 125, but not the easiest thing to ride.

    [​IMG]
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  3. sparkingdogg

    sparkingdogg Prisoner In Disguise

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    You do, of course, realize that the KDX200 is based on a KX125?? A KX125 will not be "a lot" lighter and slimmer. Somewhat, but not a lot.

    I'm no expert on KX125's, but anything around Y2K would be a good bike. Yeah, the post '04's had some upgrades (front forks better, I think) but the older ones are good bikes. Heck, I had a riot on a '94 KX125 I owned a few years ago. Fun bikes, as are the KDX200's. I weigh around 185# and the 125's are a hoot, for my size. Lack of power gets a bit boring though. They have a whole lot of rev but little grunt.

    IMO you could make a KDX200 a decent play bike, and even track bike, but you probably want the 125 if you are going to race it, due to classes. The KDX200 wouldn't be very competitive in the 250 class.

    FWIW, I have owned around 10 KDX200's and still have 3 of them, one is mint and put up in dry long term storage. I got a nice shape '93 (USD factory forks) from a fellow inmate for $800 and it's already street legal. Nearly as light as a KX125 but much better suited (IMO) for trail riding. KX125 is better suited for racing. Just my two cents. Either bike is much lightweight fun.
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  4. wfopete

    wfopete Suffer Fools; Gladly!

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    The OP has me a little confused by the thread title and what he wrote. Are you wanting to do MX or Enduro with the KX. Either way I think your biggest obstacle is your "small budget". These are 125 MX bikes and kinda old ones at that. Parts availability may be an issue. If you are looking at doing off road/enduro the typical "tall" first gear and close ratio trannies will hinder you as well as the powerbands. I could see a 125 motor wearing out in just one nasty enduro. Might be more fun in a harescramble environment. Just keeping it running will take some dough. Now if you are talking MX the suspension would be my major concern. Overall, yes, the light weight part is attractive but the rest of the story could be evil.
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  5. NDMX743

    NDMX743 Been here awhile

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    I recently bought a 99 kx125. It wasn't as slow as I remember them being. Maybe it isn't stock but it has decent power (I usually ride a 2013 kx450). The chassis is ok handling, but nothing special. Like all 125s, first gear is really low. Also it is hard to find a nice old 125. Most of them are pretty beat up.
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  6. NDMX743

    NDMX743 Been here awhile

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    Mine is beat up. It was $500. If I put $300 into it, it would be a decent bike.
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  7. tHEtREV

    tHEtREV Encouragement award recipient. tEAM iDIOT.

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    Sorry, was tired when I started the thread and can see where I was just rambling...

    The question should actually be, is the 03+ that much better than the 02, I will be using it for enduros on tight and hilly courses, and the occasional play on a motocross track (not racing, just "training").

    Looks like I tried to ask if there was any other 125 from that era that may be better in someway, and then I wondered loudly if a MX 250F might be a better choice considering I can get a much newer bike for the same money(but to be honest the real chance that it could go bang in a catastrophic way at any second, and I would probably need a new top end before I even ride it has kind of turned me off them).

    And I am aware the KDX was "based" on the KX 125, but that was an early 90's KX, as far as I know bugger all is interchangeable with any year KX, and I really don't like the way you sit in, rather than on the KDX. I like to move around.
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  8. Damifino

    Damifino Damn if I know Supporter

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    The KX 125 has very little low end grunt, you be using the clutch a lot on that bike. I got an old beater KDX a while ago, I was a KTM 200 guy all the years I was competing in enduros in the ECEA, I never thought much about the KDX's in the past, they were always a play bike to me. But after riding the now rebuilt beater KDX, I'm impressed, it's great off road. Get the KDX, put a pipe and silencer on it, re jet it and set the suspension clickers up as found on Jeff Fredette's KDX webpage and don't look back! http://www.frpoffroad.com/kdxposed.htm
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  9. AlpinaE24

    AlpinaE24 Long timer

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    I'd go KDX
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  10. sparkingdogg

    sparkingdogg Prisoner In Disguise

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    No matter what 2T you buy, unless it's a super rare affordable low hour barn find (good luck with that), you better set aside $500 for the crank shaft and engine bearings, and more if the plated cylinder is worn out. Pretty much all the 125's have been thrashed by 15 year old kids.

    It's pretty typical for the previous owners to have done zero bottom end work on these bikes. The crank can very well be at the end of spec, and need rebuilt. Not trying to dissuade you in any way, just something to keep in mind!! Unless the machine has an hour meter installed, and service records, I would assume the crank is worn out. Pretty safe assumption.

    I doubt the '03+ will be "worlds" different... I had a '94 KX125 one summer and an '01 CR125 the next, those 7 years didn't add up to light-years-ahead stuff. Probably some small (but certainly nice) differences.

    Good luck with whatever you do... be well and have fun!!
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  11. tHEtREV

    tHEtREV Encouragement award recipient. tEAM iDIOT.

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    Never ridden the newer KDX (had a 84 and a 91) but the seat and tank arrangement looked very similar to the KLX, and I found them to be really difficult to move around on the seat, it kind of locks you into one position.

    My last two stroke was an 07 Gas Gas EC250 and that had a really flat seat, it was a dream to ride when pushing it especially after coming from my old KLX or the 87 KX250 I had at the same time, part of that was motor and suspension, but the seating arrangement and ergos were the thing that made the main difference. So a flat seat tank junction is the main thing I want.
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  12. tHEtREV

    tHEtREV Encouragement award recipient. tEAM iDIOT.

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    I am well aware of the way to ride small two strokes (hold the throttle open and row through the gears), I only sold my last 125 (86 KX for VMX) about 4 years ago (I used it mainly for bush riding because there was so few VMX events in my area at the time).

    Funny you should mention the KDX KTM comparison, I always wanted a 200 EXC, and stumbled on a cheap 2000 model and grabbed it. I really wanted to like that bike but I just never got along with it.

    At the same time I had my 91 KDX, and found I would jump on the KDX most of the time and just enjoyed it way more for bush riding.

    I sold the KDX because I had to get rid of one because I was moving, and the EXC was closer to getting on the road.

    I sold it not long after the move though, and decided I wasn't a two stroke guy because everyone raved about the 200 EXC but I didn't really like it, and my first 525 was so much better in the bush.

    My Gas Gas was the bike that restored my faith in 2 strokes (and I bought that because I was looking for a KDX but they were all stupidly expensive and the Gasser was cheaper).

    I bought another EXC a few weeks ago because it was cheep, but sold it fairly quickly.

    But anyway, I'm not after a trail bike, I have a 525 for that.
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  13. Damifino

    Damifino Damn if I know Supporter

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    I had a 99 200EXC, it was miserably suspended, I loved the motor, hated the suspension, spent a lot trying to make it right, bought a 04 and it was worlds better, better suspension, better motor, it was a great bike all around.

    I rode a young man's 99 KX125 out of the woods once at our enduro, the kid got banged up and an ambulance ride, that bike had absolutely no bottom end, I had a hard time getting up a few short, steep uphills, it was a horrible woods bike.

    My son had a YZ125 when he was a teenager, that bike had a 140 Eric Gorr motor tuned for bottom end, it went well in the woods and still reved out pretty good, I rode that bike in a hare scramble once and did ok on it.

    the ergos on the last version of the KDX are much better than the pre 1995 ones, I'm able to get up on the tank pretty good on mine, and I'm not a small guy, I wish the seat to peg reach was longer, but I'm going to get a tall seat kit for, I think that may help
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  14. NDMX743

    NDMX743 Been here awhile

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    The 03 and newer kx125 is better, but not worlds better. The seat layout is pretty modern on either and way better than a klx. I have owned all of them in the last couple years. But the layout of the seat wouldn't make up for the engine. I would recommend a 250 or 200.
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  15. NDMX743

    NDMX743 Been here awhile

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    Scratch that. Buy a 125. Have some fun.
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  16. tHEtREV

    tHEtREV Encouragement award recipient. tEAM iDIOT.

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    The reason I want a 125 2t or 250 4t is to try and improve my riding.

    I used to love the smaller bikes and having to push them to keep up with everyone else who was on bigger bikes just doing the old accelerate hard out of a turn, hit the brakes for the next turn, wobble around it at a slow pace then hit the throttle when it straightens out again, while I had to hold it pinned everywhere and keep the corner speed up.

    I have shifted to bigger four strokes and found myself doing the point and shoot again.

    That and I don't want anything to close to my 525 so I will actually take it out and use it.

    And the racing always helps you get better.
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  17. Navin

    Navin Long timer

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    My suggestion... 96 conventional fork RM125 or newer. Hinson the clutch cause they were made of warm butter, the rest is very solid and lots of SX quick steering to go with it.

    Id look for the 49mm conv fork of 96/97!
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  18. tHEtREV

    tHEtREV Encouragement award recipient. tEAM iDIOT.

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    Yeah but I good a good deal on an 07 RMZ250.
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  19. Navin

    Navin Long timer

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    Then run that! Friggin old threadzzzzz!
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  20. Dao1

    Dao1 Long timer

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    One thing to remember w/ a 125 MX smoker....
    is the relatively short hours on the piston ring b/c you're having to bring the revs up to be on the pipe.
    Under race conditions, 20-40 hrs between a top end job is about the norm.

    On a 250cc, it's 40-80 hrs on a single ring, 60-120 on a double...

    on a 300cc, it's upwards of 150 hrs. on av. b/c most ride 300's a gear higher up, lugging it through the trees.
    #20