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Technical Zone

1.3k Topics 11.5k Posts

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  • Suspension Related

    100 768
    100 Topics
    768 Posts
    HOTSHOT IIIH
    @reudtr88 The seller is right, the spacers and caliper bracket are narrower than the DT125R versions. The bench mock-up in the pics above comprised a 3ET DT200R swingarm, caliper hanger and spacers mated to a DT125R hub. As you can see the 428 sprockets lined up quite well (I also had to use a 3mm thick M20 washer between the caliper hanger and swingarm to get it as good as it could possibly be with the items I had to hand).

  • Exhaust Related

    64 569
    64 Topics
    569 Posts
    D
    as far as i m aware there are 3 different types of tzr the first model series 2 (RR) an tzr125r sp i have an exhaust with the code 4DL E46 10 20 what model is it intended for

  • Framework Related

    86 606
    86 Topics
    606 Posts
    CalumC
    That's normal. All DTs are like that. [image: IMG-20251011-114625.jpg]

  • Wheel Related

    83 749
    83 Topics
    749 Posts
    R
    Just measure from the inside of the fork leg to the rim on each side, +-2mm should be ok I think. If you release the nuts on the axle clamp on the right side (if I remember correctly) and pump the front suspension up and down, and then re-tighten, it should not bind. If the seals wear out too quickly, I would check the surface of the fork tubes, so they are not damaged (pitted from rust, flaking chrome etc.)

  • Electric Related

    267 2k
    267 Topics
    2k Posts
    R
    ..and you need the battery too, not just the regulator. Forgot to write that

  • Brake Related

    70 459
    70 Topics
    459 Posts
    CalumC
    Do you mean dual piston caliper? Or do you want two calipers 🤭 https://ebay.io/m/yOnXyn Or have one made using Nevs design [image: 27961158925_26ab4db984_c.jpg] https://dt125r.co.uk/topic/1343/dt125-front-brake-caliper-bracket-dimensions/2?_=1772783708212

  • Engine Related

    549 5k
    549 Topics
    5k Posts
    CalumC
    Several options Can you not skim the head and barrel and remove the imperfections, then space the barrel with two bottom gaskets? Can you not get yourself a reusable copper head gaaket. They used to be all the range a few years ago. You could always contact an engineering firm like PJME to machine an o-ring into your setup to bypass the imperfections. https://www.pjme.co.uk/acatalog/Yamaha-DT125R-Head-Gasket-O-Ring--5866.html
  • C

    DT125 R(4BL) Parts no longer available (new)

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    1 Posts
    948 Views
    No one has replied
  • G

    Tacho reading 1500 when engine not running

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    3 Posts
    759 Views
    G
    Hi, okay, thanks @declan - may try and get it open , knowing there will be a backup plan!
  • B

    Dt 125re No power.

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    0 Votes
    4 Posts
    1k Views
    declanD
    @Baileyboy2008 well like Calum pointed out there’s no such thing as pinning your valve half way if the valve is have way closed you will get zero power above 6k open her all the way and then see what it does
  • DartyD

    The Library

    dt125r dt200wr wr200
    5
    5 Votes
    5 Posts
    2k Views
    NottsbikerN
    Yes very rare now and you have to hunt high and low to find anything at sensible prices I'm afraid
  • D

    Dtr 125 pressurizing problem!

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    0 Votes
    9 Posts
    2k Views
    CalumC
    Pressure Cap! I wouldn't believe it but I have seen it a few times. Always start off with something cheap and look at the more expensive items later.
  • Ryan FR

    Bike lacks power

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    0 Votes
    27 Posts
    5k Views
    CalumC
    @Oisin You tried searching? https://dt125r.co.uk/topic/578/derestricting-guide
  • B

    Still no spark on my DT125RE

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    0 Votes
    9 Posts
    1k Views
    CalumC
    Measure across the pick up sensor. Make sure that you are getting current to trigger the CDI. You will want to follow that pulse from the pickup to the CDI. From the CDI you will see it go to the primary coil. From there it should go to the secondary mutal winding and out to the HT lead. It's as simple as that. Somewhere you are losing that signal.
  • riley_racerR

    Stickers/Decals

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    0 Votes
    14 Posts
    2k Views
    riley_racerR
    @oldman just had a quick search, looks ideal, cheers mate
  • V

    Why does it do this?

    7
    0 Votes
    7 Posts
    1k Views
    V
    @markus-w thanks
  • V

    Should theese jets fit my yamaha dt 125 x 2006 witk mikuni tm28-92 carb (stock carb)

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    0 Votes
    1 Posts
    523 Views
    No one has replied
  • J

    Dt125re 2004 servo

    servo
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    0 Votes
    11 Posts
    2k Views
    C
    so @Jgb19830 did you fixed it,just by that? i have the same problem.
  • 2

    This sounds like bottom end bearings right?

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    4 Posts
    697 Views
    CalumC
    Well you should have checked the bearings at the same time. For up or down play.
  • W

    HID headlight conversion

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    0 Votes
    6 Posts
    983 Views
    N
    @ward4014 Just fit some brighter bulbs for a super easy and cheap upgrade; https://www.ebay.co.uk/itm/2-x-H5-P45t-Birnen-Halogen-Auto-Lampen-6000K-60-55W-Xenon-Weis-12V/362660604593?hash=item547041aab1:g:GEkAAOSw~dJdNZD9
  • W

    New piston but no rebore

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    4 Posts
    954 Views
    W
    Thanks guys I'll take it to the shop once I have it off I'm only changing the piston because I have never changed it it rides mint but just peace of mind
  • W

    How does the oil get into the gearbox side of the engine

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    5 Posts
    938 Views
    W
    @Calum I have had the clutch cover off everything looks good tbh
  • W

    Reset milage to 0

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    0 Votes
    4 Posts
    808 Views
    CalumC
    My aftermarket clocks reset to zero. Now my mot history is all over the place. I don't intend on selling the bike so makes no odds to me. Would be nice to see how many miles I have done in ten years though.
  • P

    General maintenance

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    7 Posts
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    CalumC
    @panmil92 I don't recall there being any certain type of weak point. Fairly bullet proof motors. It's just general items. Bearings, bushes and seals.
  • J

    Piston play

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    0 Votes
    2 Posts
    602 Views
    J
    https://youtu.be/p5XOQFRJzko Here it is running... Story is it overheated on a ride out due to an airlock in the cooling system. So the piston went pop
  • S

    2007 dt re blue frame colour code??

    3
    1 Votes
    3 Posts
    962 Views
    declanD
    @Minia I believe it’s on the frame tube under the rear of the mudguard
  • D

    reeds confusion ??

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    5 Posts
    932 Views
    D
    @Calum said in reeds confusion ??: @Dingle74 I'm sure there is information on here about what can be used. Try using the search bar.. good pointe with the searchthing , but the searchfunction is not my new freind :crazy_face: when searching for reeds i get everything from pics of cracked seat to chain and wheel-questions :face_with_hand_over_mouth: so have just skimmed over lightly there was one post though sayin that wr dont fit and poster wanted to show a pic of the difference but sadly it didnt work for him