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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
    83 747
    83 Topics
    747 Posts
    R
    Check that the front wheel is centered in the fork, that should be enough. There should be no binding in the fork since one side is just a clamp.

  • Electric Related
    265 2k
    265 Topics
    2k Posts
    CalumC
    I'm sure someone here will be able to point you in the right direction. What we've been seeing in recent times are a lot of DTRs being imported from Europe, these can come with subtle differences, this may be the case here. This is the 3NC wiring diagram. [image: 52172141696_84e3b69382_b.jpg] I only have a Haynes manual so can't speak for what other diagrams look like. I have also hosted the workshop manuals here: https://dt125r.co.uk/topic/3258/yamaha-dt125r-200r-workshop-manual https://training.dt125r.co.uk/files/Yamaha_DT125_Workshop_Manual.pdf This may be useful.

  • Brake Related
    68 453
    68 Topics
    453 Posts
    CalumC
    Yeah that sounds like a good idea and should be easy to swap the wheels over without too much faff!

  • Engine Related
    545 5k
    545 Topics
    5k Posts
    H
    Got it, thanks for your help everyone. Was planning to have a go but then had an episode and ended up in hospital. Now I'm back in the game.
  • declanD

    Un used crank nipple???

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    5 Posts
    2k Views
    declanD
    @castrolsniffer will do now I know what it is thanks.
  • D

    Yamaha dt re 125 2006 no power to servo

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    2 Posts
    1k Views
    Louis-DT-WRL
    Have you earthed the powervalve?
  • CallumJ94C

    YPVS Servo Problem

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    0 Votes
    4 Posts
    2k Views
    Louis-DT-WRL
    Try swapping a cdi from the other bike to rule out its the cdi
  • G

    Twin rad

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    0 Votes
    21 Posts
    6k Views
    CalumC
    @CYBER-NINJA An ally rad would make a huge difference. The Lanza rad, like the DT200R Rad, has a tiny capacity. I'm sure it ran very hot. But then the DT never had a digital temperature gauge to compare it to. The RE's Simply have a light that goes on when the engine is too hot.
  • G

    Rear coolant bottle

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    0 Votes
    6 Posts
    2k Views
    G
    Awesome thanks @Calum
  • B

    Health Check

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    28 Posts
    8k Views
    F
    Most 4 stroke bikes use the same oil for engine and gearbox, so any bike oil will be fine. But car oil is a no no as it has additives in that will make the clutch slip.
  • D

    Seized Engine after rebuild...

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    7 Posts
    2k Views
    CalumC
    @Darty I am not convinced a bit of water would have seized tge engine. Any good engine builder liberally coata a freshly built engine with lots of oil. Although now I think about it. If the leak was at the bottom gasket, and was severe. Then haven't you juat hydrolocked the engine? Clearly it neess investigating so until you split the cases you won't truly know the extent of the damage.
  • 8

    Need a speedo drive

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    0 Votes
    6 Posts
    2k Views
    tunertomT
    https://www.ajsutton.co.uk/product/yamaha/3XP251900000/gear-unit-assy?uid=0 go here... go to the tab that says fitment, it shows the part number and all the same bikes that use the same speedo as the DT.
  • Uber_BelugaU

    Chain and sprockets

    12
    0 Votes
    12 Posts
    8k Views
    Uber_BelugaU
    Alright, that's a no to the higher pitch in that case. Doesn't look like I'm going to get any of this stuff before the weekend now. I have a whole heap of new stuff that I'm dying to get on the bike, so the drivetrain stuff is going to have to wait I think. If I can get the bike running this weekend I'll place an order for one of those anodised renthal rear sprockets, a 428 chain and a standard front sprocket. I'll probably come back and ask about chains then. Here's hoping I can get a spark this weekend.
  • MiniaM

    In need of speedos for DT125R

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    16 Posts
    8k Views
    CalumC
    @CYBER-NINJA I was going to say bet they weren't cheap. They look mint though.
  • M

    DT125R SM suddenly cut out,Now wont start.Powevalve has stopped cleaning cycle

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    8 Posts
    3k Views
    CalumC
    @MattD thatis fine it will do that.t
  • Uber_BelugaU

    Difficult start

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    25 Posts
    19k Views
    R
    @Uber_Beluga So if you have four wires - one will be an ign. Switched live to the starter switch. One will be the return wire to the starter solenoid. Then the other two will be a feed up from the CDI and a return that either goes back to the CDI to make a circuit or maybe goes to earth as I mentioned before. Just buzz the wires out with your meter to check what they do, but if you can get a good make/break across the switch then that's not you problem.
  • Uber_BelugaU

    Good mechanic for DT or 2 strokes in general

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    21 Posts
    10k Views
    CalumC
    @Uber_Beluga Alright mate, well feel free to PM me any time. And as always, if you fancy doing it yourself, throw up a thread if you need help. Either myself or someone will be around to fire some answers.
  • vtrtomukV

    Renamed, Head Gasket Leak, Solved

    35
    0 Votes
    35 Posts
    26k Views
    CalumC
    Clutch needs to be balanced properly if it's dismantled. But But noise is generic. Is it metal on metal sound?
  • D

    Best modification and why?

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    7 Posts
    4k Views
    CalumC
    @DevonDtr Even I don't do those hours! Still £50 better off in your pockets. But if you are happy to pay then by all means.
  • Leftyno1L

    Bike will start but not Tick over ?

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    24 Posts
    18k Views
    CalumC
    @Leftyno1 yeah nice one man. Yes and no. Of course when the clutch wears significantly it will slip. But it will not disengaged before it slips so theres that. What I mean is when the clutch is on ots way out. With the clutch lever pulled in the clutch with not disengage and still pass power to the wheels. You them adjust it to its max setting on yhe lever, perch and clutch drum. If that still fails then new plates amd springs. But I mean you would need serious mileage before that happens. By which time you will do a full engine rebuild and why you wouldn't build yhe clutxh at that stage is madness.