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Found 15 results

  1. Hi All, Recently I purchased a 2012 125sx from a friend dirt cheap. The only catch, the thing would occasionally seize up. I finally got around to slitting the cases on it and this is what I found. 30-40 loose ball bearings around 4-5mm in diameter, most of them on the transmission side(I gathered most of the ones i could find for the picture below). What I didn't find where any bearing races or any indication of where these may have come from. Now I have little experience with these machines, but common sense tells me I should have clear failure of multiple bearings to produce this many loose balls. While it is unlikely, someone could have vandalized this poor bike with a handful of BB's for a BBgun. My question to you fine folks: Where do you think these BBs came from? Am i missing something obvious? Thanks for your time. External link for pics: https://imgur.com/gallery/yR40O76
  2. My 2016 KTM SX 125's seat is too narrow, so the plastic pretrudes out just where my knee is. This means it's not only painful to grip the bike, but i don't get any extra grip out of it, and end up supporting myself mith my arms, which is not exactly ideal when riding. This would not be a problem if my leg was shorter as i would then be able to grip the plastic, but as my knee is right on the edge i get no grip. My local dealer doesn't sell any aftermarket seats so i haven't been able to see if any of them are wider. They say they don't want to pack some extra foam inside as they say it wont last, but anything is better than this. I'm planning to drop by my dealer tomorrow to check out the other bikes, and whether they have the same problem or not. I took some measurements of my seat and bike so you can hopefully compare them to your bike. The seat is approximately 16,5 cm at its widest, and the bike is 18,5 at its widest. If any of you by chance have a wider seat than this please tell me, looking at bike images on google to see if the seat is narrower than the bike is not easy. And if you have any ideas as to what i can do please tell me. Thanks in advance
  3. Hey everyone recently picked up a used 2005 KTM 125sx. Had not been cleaned in a while so i gave it a power wash. Only thing wrong with it are small fork seal leak, worn out rear shock bearing and worn out seal where the expansion chamber connects to the engine. Where the carb connects to the reed it looks like it has small cracks on the plastic (is this bad), ill put in a few images in the post. (1) So firstly can i ride the bike with leaky fork seals (will this damage the forks), (2) can i ride the bike with a rear lower shock bearing in need for replacement (has play in the swing arm when on a stand), (3) how can i tell if it has a counter shaft leak and that its not just chain lube, (4) is there anything i can use to temporarily fix the expansion chamber leak, (5) how can i check the piston with out taking the whole engine apart, (6) the last owner was running the bike 20:1 (yikes) could this have damaged the bike and how can i drain the fuel tank and lastly (7) how can i get some small bits of surface rust and oil off the expansion chamber. Thanks for reading hopefully i can get some questions answered!
  4. I´ll keep it short, i want to spend about $3000 on a 125 used 2t bike. Should i consider buying one from around 2006-10 for like $2000 and sticking money into it, assuming its going to needs a new top end, pegs, levers etc. Or do i go with a more expensive bike thats maybe a little newer and not spending a ton on it. if i were to go with a bike that was a little older, what brands and years were known to be pretty good? i think with a newer bike id go with a 2015+ yz125 anybody got any ideas?
  5. Bobby Mccann


    I have a 04 ktm 125sx. I want to get a new tank on my bike but it looks like they don't have any black ones for the 125sx but they do for the 200sx. I was wondering if It could fit?
  6. Hello all, Heres a little background...I used to do all my own wrenching about 20 years ago, but have been out of the game for a while until I bought this bike last year. I have a 2002 ktm 125sx and am looking to rebuild the top end. The Piston has "53.940" stamped on top, and the jug measures 54.03mm. what size piston should I be buying? I'm seeing a lot of pistons at 54.000mm but am concerned that may be too tight. Also, are the rings different sized also? All of your help is greatly appreciated! Hoping everyone is staying safe during this crazy time!
  7. I'm and intermediate rider who rides very aggressively and on hard, but fast-paced woods/cross-country/harescramble riding. Sometimes I'll do technical, really tight trails, log crossings, and hillclimbs, etc. and I also will ride motocross tracks every once in a while. I currently own a 2008 KTM 250 XC-F with a bigger rear sprocket, FMF exhaust, aftermarket piston, and I typically run high octane fuel. I won't be upgrading for quite a while but I am planning ahead trying to decide what to save up for and all that. I'm sure this forum will also help others in similar situations. I'd like something that can top out faster than my bike but something that can accelerate quickly and have more torque as well. The majority of my riding is very fast-paced woods with hard corners and lots of roots and steep hills as well, so I'd like something that can blow through corners and accelerate quickly. But, I also ride a lot of tight technical trails so I'd like something that's torquey and has explosive, yet controllable power and something I can take over big logs and rocks. I'm fine with a bike that likes to be revved a lot as that's what I do on my 250xcf now. I'm used to four strokes although I'll probably adjust to a two stroke very quickly as I ride constantly. I'm leaning towards a 250 XC or a 350 XC-F although I've heard lots about KTM's 125 and 150 2 strokes, the 450 and 500, the wide ratio "w" models of the cross country bikes, and their respective motocross models just because I know how explosive they are. I understand that this is a lot to ask out of one bike but I'm going to be adding a lot of aftermarket parts to whatever I end up getting if it doesn't already have any. Tell me all about these bikes if any of you guys have ridden them! I'm probably going KTM because I've heard nothing but good things about them but I will still consider any other brands as well. Tell me any aftermarket you had to do, improvements to be done or downfalls of each bike, and all their advantages and things they're better at than the other ones if you've ridden more than one of these. This is more of a harescramble/cross-country racing post, but since some of my races have parts of motocross tracks I'd like to hear how they do on the track. Also, money isn't too huge of a concern with me but I will definitely not be able to get a brand new bike. I will be racing so if it's bigger than a 250 then I'll have to be sure that it can compete with bigger bikes. Thanks, in advance!
  8. Right now I have a 2004 ktm 125sx, here’s a little background of it, it has a ported head, Barnett clutch, and a 6 gear added, the 04s came with 5 speeds and it didn’t cost too much to add the sixth so I did! The question I’m asking is should I get a ktm 250sx I’m tired of over reving it and all I do is trails and hill climbs I weigh 130 and 5,8 kind of worried the 250 will be too much weight for me but want someone’s opinion on this, parents are not too amused with the idea of getting a bigger bike but I think it would just make my life easier with the torque! Should I keep the 125 for longer or get the 250?
  9. Okay so I just bought an 09 125sx for trail riding and want to add a larger tank. Unfortunately an over sized tank is anywhere from 230 - 300$. So I thought about buying a used one off ebay, does anyone know if 200/250/300 exc fuel tanks are compatible from the same year or what other years are compatible with it?
  10. I just bought a 2003 KTM 125 SX from craigslist the guy I bought it from only owned the bike for a couple weeks but the guy who owned the bike before had supposedly just rebuilt the top end, I also believed he probably raced with it cause hes got his name on the decals and numbers on it. When I went to pick it thought it sounded fine but I'm not familiar with 2 strokes and I showed it to my Dad and started it up and he pointed out a noise that sounds kind of like a rattle or something and I'm not sure if that is just a normal noise for this bike or if there might be an issue that I should look into. Also the bike looks really clean its got a new fmf pipe on it and supposedly new boysen reeds but the day I brought it home I went ahead and did an oil change and it was verrrry dirty. If anyone is familiar with this bike or has any advise I would really appreciate it!!! Thank you!! Here is a link to a video of the bike running
  11. I just bought a 2004 ktm 125sx and it is a very clean bike. I have ridden it only a few times and i noticed a weird studder or kind of bog when in mid to high rpms and the bike cuts out for a second and then cuts back in a split second. I cant figure out what it is doing this. I keep air filter clean, new spark plug, good gas. I use an NGK BR9es, the manual says to use NGk Br9evx. i have read it could be powervalve, jetting, maybe silencer packing, im not sure. please ask any questions, i really want to figure this out. thanks
  12. My son rides a 2018 125sx in cross country hare scrambles. Two weeks ago, an hour into the race, he refueled in the pits then continued on...bike went about 100 yards than quit. Bike would start with choke on but wouldn't stay running. We cleaned the carb, changed the spark plug, replaced the fuel, and replaced the air filter. We got it to start and it ran okay as long as the rpms were high. Entered another race last week and the bike ran great until an hour into the race he refueled and the bike died about 5 minutes later and wouldn't start (same as the previous week). Completely frustrated, we bought a brand new 2019 150sx. We broke it in last week and yesterday entered another cross country race. Bike ran great but than quit an hour into the race after refueling in the pits. Same symptoms as before. It won't start. We are mixing the fuel 40:1 and running 98 octane fuel. Don't know what we are doing wrong. Any advice is appreciated.
  13. I want to put lights on my 2019 KTM 150sx to make is street legal and was wondering if anyone knew what I would need to do to hook some lights up and how much it entails.
  14. I have a 1998 ktm 125sx. I am completely stumped on this clutch. When I first got the bike, the clutch was weak. I bleed it and it was good for a little bit. Then it went out again. So I tried bleeding it again and nothing. Then I tried reverse bleeding it. Nothing. Then i replaced the o-ring on the slave piston. Nothing. Now this might sound crazy, but I put dye in the oil to find the leak. It seems like it’s now leaking from the line in from the clutch. I’m trying to flip this bike and am already into it more than it’s worth and don’t want to buy a braided clutch line. Does anyone know how to connect or seal this line at the connection. Here’s a picture of where I’m talking about. Thank you
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