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About Twizzlerbones

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  1. My clymer manual suggests 24:1 for it, so I'm very away it's not right. You can run less oil, you just have to jet for it. Oil has improved a lot since this bike was in production and running those rich ratios is not necessary, provided you can get it jetted right. And it's running rich at 1/4 to 1/2 throttle for sure. Richening the needle makes it worse and leaning the needle makes it feel dead. It needs a different needle.
  2. I am having some trouble with an old 1992 yz125 I have been working on. I think I have narrowed it down to the needle. Im trying to jet this bike at 60:1 so that it will run on the same gas as my KTM, and I do understand my problems are stemming from there. It runs good everywhere except 1/4-1/2 throttle, where it runs quite rich and bogs. Leaning out on the needle clip position even just one position really gives the bike a dead mid range feel. So I'm thinking I need a different needle that is going to lean up that part of the throttle but not outside of that. Here's what I currently have in the mikuni TMX carb with a 60:1 oil ratio at about 5000' elevation. Main Jet: 220 Needle position: 3rd (I believe it's the stock needle) Pilot jet: 12.5 Let me know what you guys think, I'd like to keep it at a 60:1 ratio, but I'm sure I'm going to need a different needle to get it running right at that ratio. I would love some recommendations on needles to try.
  3. It certainly sounds carb related to me. Your bore in the cylinder looks fine. Definitely check float level and the pilot jet. Check spark after that.
  4. The shaft at the bottom of the shock next to the linkage is bent pretty bad, throwing off the geometry slightly and caused it to wear out the seal and lose all it's oil. I could definitely get another 93 shock off eBay and rebuild it, but if I have to do that I'd obviously prefer a newer shock if they are better and will bolt up.
  5. I picked up an old 93 cr125 a few months ago, and the rear shock needs some work. I was curious if the later cr125 model shocks were better and if they are direct swaps on the bike, if not how hard is it going to be get it to fit? Also how hard would it be to get a newer CRF shock to fit? Any suggestions are welcome! Thanks guys
  6. I apologize, I was being a dummy, it was 310 that was in there not a 410, now a 315 and the mid range is much better with the 315. 320 was too rich.
  7. That's for the 24:1 fuel mix that the manual recommends and i don't run that rich of fuel. Oil has come a long way in 30 years, and I don't think you should run that much oil anymore. I run 50:1 with Motorex cross power. The 415 definitely runs better than the 410 did. I'm also in Utah at 5000 feet
  8. Float level seems ok, these TM carbs are finiky with it
  9. I thought maybe it was running lean on top, I went from a 410 to a 415 (mikuni) and it did actually feel better in the mid, then I tried a 420 and it felt a little rich so I put the 415 back in. Right now I run 415 main 20 pilot 2nd needle position from the top.
  10. So the silencer is an FMF powercore for a KTM 380 that I had to modify to fit the bike (there aren't any silencers still in production for the 1992) and the packing was just changed out on it about a month ago. I did take out both jets, cleaned them and the carb and went up a few sizes on the main jet. I took the reeds out and they look good. The only thing I could think of was the crankseals. It could be the silencer, due to it being for a completely different bike, but it sounds and feels awesome in the low to mid range. It's only when you try to get the RPM's up that it will essentially fall on its face.
  11. Here are some better pictures of it. It does not appear to go all the way through
  12. I spent hours looking through those, I have no idea what this hole could be for. Maybe I'll see how it runs with a set screw in there, I don't think it could hurt anything.
  13. This may be a stupid question, but I'm rebuilding a 1992 YZ125, and the thing has a weird bog on top, I've tried playing with the main jet and needle with little to no improvement on the bog on top. I also rebuilt the top end (rebore and piston). I figured I'd replace the crank seal on the clutch side (I assume the ignition side seal is fine because it has no oil in the ignition cover anywhere) to see if that gets rid of the bog. Once I pulled the clutch cover off I noticed this threaded hole next to the power valve timer bearing that goes to the intake by the reed cage. Should I put a bolt/set screw in there? This is my first Yamaha, and none of the KTM's I've worked on had one of these. What is this hole for? Could the hole be causing the bog?
  14. Hey guys, I just picked up an old 1992 YZ125 that I'm rebuilding. It didn't come with any silencer. I was wondering what other Yamaha bikes share the same silencer? I know that my KTM 380, I was able to fit a silencer from a 2011 KTM 300XC on it with no modifications. I'm mostly just wondering at what my options are for it as I would like to not have to put a stock silencer on it. Pro circuit use to make a 304 silencer for it, but it seems to have been discontinued. I am willing to do modifications if needed to get a quality aftermarket silencer on it.
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