DT125R FORUM

Thanks for the detailed Calum, i must say i was expecting more from this kit, the midrange is a improvement and is quite fun, my expectations on it being rev happy were obvously missplaced. really annoying that Athena Dont provide a base jetting range to start, jetting should be done per bike and mods etc, but a rich basline would be nice info i got was from here, youtube and https://www.rrd-preparation.com/en/kit-high-engine-motorcycle-125cc-2-times/671-kit-170-cc-athena-racing-for-motor-125-derbi-gpr-yamaha-tdr-dt-tzr-2-time.html if anyone stumbles apon this thread some keep the pilot the same but most go up a jet size.to 25 and the main is recomended to be between a 170-190 go 190 if your running in as a newbuild. on that note have noticed my silencer packing is a bit oily probably from running a 27.5 and 320 main so ill get that repacked could be chokeing out. the ignition system will be a future investment, when funds allow

Hi Glenn welcome to the Forum. It's very quiet on here these days, everything migrated to Meta a long time ago, but I feel the real enthusiasts will remain here :) Sounds like you've got a wealth of experience with these bikes, almost feels criminal to be breaking them nowadays though, price of them are soaring.

glad you got it sorted with the round slide carb fitted now bud

Oh okay interesting, are you able to fit a kick start and ditch the starter motor? The DTRE has a starter so maybe that frame is a better fit.

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

A Chinese one would do enough for what it is... A dirt bike older then me waiting for it's resting day

I'd would just listen to hotshot-iii - https://dt125r.co.uk/topic/3551/do-pipercross-air-filters-really-flow-better-at-all I haven't ran an airbox on my DTR for 10+ years and I just used the stock filter the time I had it. So I don't have any opinion on it.

@Calum said: These were almost a nightmare to source 16 years ago, I can't imagine trying to source one now. My bike was stolen in 2010 and they smashed my headlight, the only one I could find at the time at one of the lugs snapped off. Looks like there is one for sale on eBay: https://www.ebay.co.uk/itm/117220896053?_skw=DT125re+headlight&itmmeta=01KTM8B5217RAZTYS7W99928FR&hash=item1b4ae8ed35:g:y7gAAeSwpAdqHbG7&itmprp=enc%3AAQALAAAA0GfYFPkwiKCW4ZNSs2u11xBZmLIU--K9J71U9lN1jJvKGElmcMKBjUzhn5JV3gvFr%2BI2mNwns0SlbUycS%2Bw9y3Qsk%2FC9Cp56dPrHcSEz%2FAr0Zq5el9BEEdpE--23lnRC8fU0%2Fsn13ryM871mf1jmM1dUjkmiSvaLNgJjb67pd3KfdVjuND8nPx720y4ajz9BPqgS8GUW%2FCNLpWF1MTDMkYcIXC7cHLcpOan7woIP1A2k2vjESEOPdlk4W2oy4yUcxyO%2BXWy347GqH%2BHrWnu%2F2Og%3D|tkp%3ABk9SR5bRrIjVZw Looks like there are some copies on eBay as well: https://www.ebay.co.uk/itm/188014865985?_skw=DT125re+headlight&itmmeta=01KTM8B521KCQCFP6HVFB9B97Z&hash=item2bc68f2e41:g:v4oAAeSwOt5pf0Q6&itmprp=enc%3AAQALAAAA8GfYFPkwiKCW4ZNSs2u11xBGAd3jIpQ1I%2FPeoct0WRAbZx%2BSpsbDaUmQIjZgqRPgUJo7nG5bGWKGBRZtJJ4k6kWqRTJdLi2QjCbWA%2FBE6jgcnSjbxqmpxc5alD7AkePHPryhwNx3wJMQx9Nn2c%2FJBb%2FaX0A7Z%2BlEzJ6pVoqrlh3sZUh2UZ%2BqkVZwe2vBfwA2F39HuV9O1D2z%2FSIMHbNWWFAOiiE%2BG%2F8xlRqkrAHFOwt3oKAIwYBpeHVG82hZBHdODyJwGkKG5Ef9gkphJk0fgSnlvoW%2FpV6wkCrHIDEqggbFJ3LfV5W5qwYpTWvJNjb1RA%3D%3D|tkp%3ABk9SR5bRrIjVZw Thanks for helping and sorry to hear about the theft/ damage. I had a different bike stolen around the same time period and wasn’t so fortunate with them burning it 2 doors down in a wheel barrow - I can only assume the chain & locks were giving them trouble. I purchased the unit from the first link as it’s stock and doesn’t look in too bad shape - I’ll hopefully be able to do some sort of refurb with the damaged unit I have right now and keep it as a spare now knowing their scarcity. Thank again! - one step closer to getting her back on the road.

That's right, I forgot about the clutch switch!

@lucasg.03 Take off the stator cover and see if you can see a dribble of goop coming from the seal behind the flywheel (also possibly a good time to get a flywheel puller if you don't already have one, I think Yambits sell one). Once you take off the flywheel and stator you can replace the seal in situ as long as you're careful not to mark the sealing surface of the crankshaft.

Clutch can make noises too, for example if the rubbers between the gear and clutch cage have gone bad. Check the play if you remove the cover.

I can recommend one smelling of strawberries: https://www.ipone.com/en/eshop/product/r2000

If you look at the coolant reservoir at the rear, you will notice that it has a hose going to the frame. I take that to mean that the coolant is routed via the frame tubes. Pipes. There is no hint of an explanation in the workshop manual, though. Perhaps you have a crack in the frame?

I would say so. Is quite similar to the factory headlight, but it gives the modern look I was looking for, with a cleaner and whiter light.

Well this last month a disgusting amount of money was dropped on parts for this engine. [image: PXL_20260514_154633826.jpg] Two Keihin PWK 28mm Carbs Two Vforce Reed Blocks Billet Inlet manifold EBC Clutch Kit + Heavy Duty Springs 6 TZ750 Genuine Clutch Springs Zeeltronic Ignition System Billet Kick Starter Lever Magura Hydraulic Clutch Lever Chariot Performance Billet Clutch Basket Wiseco Blaster 200 Piston (573M06800) Modified Idle Gear with bearing [image: PXL_20260519_090422306~2.jpg] [image: PXL_20260519_090204554~2.jpg] These Wiseco pistons replace the stock Athena pistons due to the 115mm long rods I'm running and the +4mm stroked crank shaft. The head still needs to be machined to accommodate the longer stroke and the wrist pin on these pistons is different to accommodate the longer rod. [image: PXL_20260512_082334371~2.jpg] This idle gear is lovely, totally unnecessary but was only £60 but seemingly not available to purchase anywhere I looked. [image: IMG-20260507-WA0005.jpeg] The Magura wasn't cheap, but it's going to be necessary when running all 6 TZ750 clutch springs just to keep the power from slipping the clutch. [image: PXL_20260530_084354385.jpg] (the other two springs are in the post I had to source elsewhere). Now that I have the basket, I can finally assemble the clutch basket with my straight cut primary gears. [image: PXL_20260519_091147857~2.jpg] Basket is beautifully made, claimed to be the best on the market and I can see why. It was missing the Belleville washer that sits between the basket and the fastener plate, I bought a genuine basket to chop up and salvage but it wasn't on that basket (apparently they're fitted to 1986 models and later). I managed to find a company that sell them so ordered from them and fitted. Wasn't cheap but I'm glad it's in. [image: PXL_20260519_091204926~2.jpg] [image: PXL_20260527_182919884.jpg] I did replace the steel bolts with some lighter titanium ones (hopefully they withstand the abuse the basket is going to take!) [image: 20260522_143841-COLLAGE.jpg] About 50% of the weight, but hopefully not at the expense of strength! [image: PXL_20260527_183632013.jpg] The washer is installed with the raised edge facing you. The fastener plate will clamp down onto this edge. [image: PXL_20260527_183640084.jpg] [image: IMG-20260530-WA0000~2.jpeg] Engine is coming together nicely now though.

Well sounds like a fantastic purchase. I thought I recall the 3SH models being quite sought after and sounds like a good buy for the money. Sadly Imgur is blocked in the UK so I can't see the images right now, I'll have to have a nosey on a VPN. Yeah, there is an okay aftermarket scene for tuning, anything that'll fit the DTR engine will fit the TDR engine. It's the TZR 125 (2RK???) models that had different engine setups, but the TZR Belgarda shared the same platform as the DTR.

No, the 4DL would have a straight inlet. These don't fit the DTR as thr carb then fouls the shock absorber.

Reposting images as Imgur not longer viable in the UK. [image: 29%20-%20aeJ7dpP.jpg] [image: 391%20-%20Elm16nL.jpg] [image: 407%20-%20Etf45f7.jpg] [image: 422%20-%20nJIkR7P.jpg] [image: 482%20-%204RdpoUd.jpg] [image: 51%20-%20M0Y9O7s.jpg] [image: 620%20-%20QFttJQk.jpg] [image: 705%20-%20RgaLCpk.jpg] [image: 87%20-%20xrd1mRZ.jpg] [image: 30%20-%20WYp7ieO.jpg] [image: 392%20-%20qy459Cg.jpg] [image: 408%20-%20oxN86Bp.jpg] [image: 423%20-%20DI9we5i.jpg] [image: 483%20-%20JhcvpI5.jpg] [image: 52%20-%20S0unjtI.jpg] [image: 621%20-%205FmdBEj.jpg] [image: 71%20-%208gCFFMK.jpg] [image: 88%20-%204wUdVrL.jpg] [image: 322%20-%20uHpSyfQ.jpg] [image: 393%20-%20aMt2eTN.jpg] [image: 409%20-%20JGiaLMj.jpg] [image: 424%20-%20PlECcjd.jpg] [image: 484%20-%20YuUXiAh.jpg] [image: 53%20-%20diWmTh1.jpg] [image: 622%20-%2022JfrAM.jpg] [image: 72%20-%20IAOJAsf.jpg] [image: 89%20-%20QOAgBIC.jpg] [image: 323%20-%20SlFW3Wz.jpg] [image: 394%20-%20RZaFDkN.jpg] [image: 41%20-%20boECUcv.jpg] [image: 425%20-%20TeFmrhU.jpg] [image: 485%20-%20KIsVZEb.png] [image: 54%20-%20oEepy7N.jpg] [image: 63%20-%20xXt4iZb.jpg] [image: 73%20-%20LjLnuEp.jpg] [image: 90%20-%205fMZDZa.jpg] [image: 340%20-%20fjnvxml.jpg] [image: 395%20-%20uB5h9lU.jpg] [image: 410%20-%20x1ns9nT.jpg] [image: 427%20-%204RsMsSG.jpg] [image: 486%20-%207BIOEzD.jpg] [image: 55%20-%20eLbUBNS.jpg] [image: 64%20-%203q0LUYx.jpg] [image: 74%20-%20OVaOZaY.jpg] [image: 91%20-%2078mDXh8.jpg] [image: 341%20-%20JAiGBgu.jpg] [image: 396%20-%20aFNCsHN.jpg] [image: 411%20-%2087Bh4JH.jpg] [image: 43%20-%20A9ZFr9M.jpg] [image: 487%20-%20oTYbXp0.png] [image: 56%20-%202kIpPOs.jpg] [image: 641%20-%20cR35P3J.jpg] [image: 75%20-%20Zsim2l1.jpg] [image: 92%20-%20fj5GWkG.jpg] [image: 342%20-%20xp34p3D.jpg] [image: 397%20-%20SFjPYVf.jpg] [image: 412%20-%202Eu3khi.jpg] [image: 44%20-%20Lw3YKPn.jpg] [image: 488%20-%20R9IIqld.jpg] [image: 57%20-%20n7HArLS.jpg] [image: 642%20-%20m2UscTS.jpg] [image: 76%20-%20DIA2hn6.jpg] [image: 93%20-%20DGyefXC.jpg] [image: 348%20-%20bCFo5Qc.jpg] [image: 398%20-%201KL3Hjc.jpg] [image: 413%20-%20fjLMI2o.jpg] [image: 45%20-%20ggMFifP.jpg] [image: 489%20-%20aYxVVVc.jpg] [image: 58%20-%20cmurYYm.jpg] [image: 643%20-%207Nvfxxs.jpg] [image: 77%20-%20cykyKhf.jpg] [image: 94%20-%20ahyvTSO.jpg] [image: 35%20-%20awrLq4S.jpg] [image: 399%20-%201BvAgCF.jpg] [image: 414%20-%20KakTMsr.jpg] [image: 451%20-%20rivlvtv.png] [image: 49%20-%20PUYW8rb.jpg] [image: 59%20-%20AMSDO5d.jpg] [image: 644%20-%207My832E.jpg] [image: 78%20-%20sydA5qF.jpg] [image: 95%20-%20GaEPXUf.jpg] [image: 36%20-%207qNpHnU.jpg] [image: 40%20-%20kn9AcmC.jpg] [image: 415%20-%20LLKQtHi.jpg] [image: 46%20-%20RcmQjQj.jpg] [image: 490%20-%20ZKk8B6k.jpg] [image: 60%20-%20GogAmiH.jpg] [image: 65%20-%20dbHTX8d.jpg] [image: 79%20-%205o22WE2.jpg] [image: 364%20-%20GqmLweA.png] [image: 400%20-%20Gd1cBqH.jpg] [image: 416%20-%20sZqHhRs.jpg] [image: 47%20-%20dU5KBCn.jpg] [image: 491%20-%207nwKlrY.png] [image: 609%20-%20XNa7cBl.jpg] [image: 66%20-%20IYMJ0BK.jpg] [image: 80%20-%209T4T589.jpg] [image: 37%20-%20nl3pbft.jpg] [image: 401%20-%2063x62oS.jpg] [image: 417%20-%20qzuxswz.jpg] [image: 477%20-%201AiUAiD.png] [image: 492%20-%20AF8eK18.jpg] [image: 61%20-%20mvbEC0O.jpg] [image: 67%20-%200cY6qTi.jpg] [image: 81%20-%20R95OfdJ.jpg] [image: 38%20-%206gjUUIX.jpg] [image: 402%20-%20KkhYqCW.jpg] [image: 418%20-%20Gpn0uRi.jpg] [image: 478%20-%20nPxy3vU.jpg] [image: 493%20-%20EUKpYyU.jpg] [image: 610%20-%2032ingBz.jpg] [image: 68%20-%20x2YHagY.jpg] [image: 82%20-%20enhpww8.jpg] [image: 386%20-%20cxbpyAe.jpg] [image: 403%20-%206nM2P9o.jpg] [image: 419%20-%201tG1xqV.jpg] [image: 479%20-%20EfkkD4y.jpg] [image: 494%20-%20DqzZRxe.jpg] [image: 611%20-%20KT6nA4s.jpg] [image: 69%20-%20ztIxxrJ.jpg] [image: 83%20-%20m3HdOdn.jpg] [image: 389%20-%20gSaRBRn.jpg] [image: 404%20-%20Kbxz5kQ.jpg] [image: 42%20-%20QXiwqtk.jpg] [image: 48%20-%20UwOTkds.jpg] [image: 495%20-%20WWXpNS7.png] [image: 612%20-%20FCnqv4M.jpg] [image: 70%20-%20TtVqeXt.jpg] [image: 84%20-%20Ev6hEKM.jpg] [image: 39%20-%20Rknb6jj.jpg] [image: 405%20-%20nq6uist.jpg] [image: 420%20-%20ATjSpQx.jpg] [image: 480%20-%201UwbRr0.jpg] [image: 50%20-%20HGJNOne.jpg] [image: 613%20-%20Oblq0qZ.jpg] [image: 703%20-%20MR6pTAM.png] [image: 85%20-%20q2AbgLX.jpg] [image: 390%20-%20ISeIeKJ.jpg] [image: 406%20-%20FTkTvKj.jpg] [image: 421%20-%20LYTSeOU.jpg] [image: 481%20-%20uH3wBkI.jpg] [image: 506%20-%20d0LFdbW.jpg] [image: 62%20-%20lNHKoYv.jpg] [image: 704%20-%20r1MRWBb.jpg] [image: 86%20-%207o6WnJ0.jpg]

Reposting images as Imgur no longer viable in the UK. [image: 507%20-%20ahhYMAV.jpg] [image: 530%20-%20HiCXC0j.jpg] [image: 536%20-%20leIJ7lX.jpg] [image: 542%20-%2072nlAsp.jpg] [image: 548%20-%20BmR50v9.jpg] [image: 554%20-%20I98okMj.jpg] [image: 560%20-%20gMIA9W1.jpg] [image: 566%20-%20AAhtSIJ.jpg] [image: 572%20-%20eQrEf5r.jpg] [image: 525%20-%20vYwhsZ4.jpg] [image: 531%20-%20Zr5VhXc.jpg] [image: 537%20-%205NCbHEK.jpg] [image: 543%20-%20ANsnPf7.jpg] [image: 549%20-%20xRM4BYZ.jpg] [image: 555%20-%20DU2szdK.jpg] [image: 561%20-%20oGUnRV3.jpg] [image: 567%20-%20dXvDqft.jpg] [image: 573%20-%207O8TJxM.jpg] [image: 526%20-%20CUfbGT3.jpg] [image: 532%20-%20Lgmi1fz.jpg] [image: 538%20-%20XOuR8bC.jpg] [image: 544%20-%20BTHEMKH.jpg] [image: 550%20-%202NkDnu5.jpg] [image: 556%20-%20M38YVVU.jpg] [image: 562%20-%20yHvzRXZ.jpg] [image: 568%20-%20nOyAdlG.jpg] [image: 574%20-%20HR9eM8S.jpg] [image: 527%20-%20XzXj2Pd.jpg] [image: 533%20-%202u5B7o2.jpg] [image: 539%20-%20Ff3zEzr.jpg] [image: 545%20-%20SIUMll0.jpg] [image: 551%20-%20BOjpBHn.jpg] [image: 557%20-%20ODWI634.jpg] [image: 563%20-%20DLkSgjO.jpg] [image: 569%20-%20w80ukUg.jpg] [image: 575%20-%20qQjDAfH.jpg] [image: 528%20-%20joltsgS.jpg] [image: 534%20-%20n09ORnT.jpg] [image: 540%20-%20iy3pxJJ.jpg] [image: 546%20-%20lBAaOm4.jpg] [image: 552%20-%206Cxgsk7.jpg] [image: 558%20-%20gzKq6zs.jpg] [image: 564%20-%20t8yAfL3.jpg] [image: 570%20-%20BGqozKz.jpg] [image: 576%20-%20KtZbFfW.jpg] [image: 529%20-%20mS47wbz.jpg] [image: 535%20-%20Eh1YUjR.jpg] [image: 541%20-%20V6uEQ9H.jpg] [image: 547%20-%2036SNa2q.jpg] [image: 553%20-%20w4i6RiZ.jpg] [image: 559%20-%20aFuP1z3.jpg] [image: 565%20-%20R04SDeo.jpg] [image: 571%20-%20xhat3cF.jpg] [image: 577%20-%200pt2AkT.jpg]

Reposting images as Imgur longer viable in the UK. [image: 426%20-%20z8X4MA8.jpg] [image: 432%20-%20cIB3ihU.jpg] [image: 437%20-%20EkRFDLn.mp4] [image: 444%20-%20X1Tp1hy.jpg] [image: 449%20-%20WDcVoDR.jpg] [image: 655%20-%201IX9tbu.jpg] [image: 660%20-%20iFH9zSC.jpg] [image: 665%20-%20yMjB5A6.jpg] [image: 428%20-%20Ekc1MIb.jpg] [image: 433%20-%20uUIpD9T.jpg] [image: 440%20-%209SPg3Bp.jpg] [image: 445%20-%20pwTT0dH.jpg] [image: 450%20-%20Ecrtcbd.jpg] [image: 656%20-%20g1RDwxa.jpg] [image: 661%20-%20RPp4LsA.jpg] [image: 666%20-%20sakiJee.jpg] [image: 429%20-%20fUlOmQh.jpg] [image: 434%20-%200kcGkbK.jpg] [image: 441%20-%209EWjTJL.jpg] [image: 446%20-%20a5vfthp.jpg] [image: 459%20-%20FZyQaWB.png] [image: 657%20-%20secyLjL.jpg] [image: 662%20-%20Ahkbrdo.jpg] [image: 669%20-%20bWIASOf.jpg] [image: 430%20-%20Mv4bb73.jpg] [image: 435%20-%20JVKKTzg.jpg] [image: 442%20-%20c6xaqQE.jpg] [image: 447%20-%20E5eE1FU.jpg] [image: 640%20-%209tkl1ib.jpg] [image: 658%20-%20mLNN6NF.jpg] [image: 663%20-%208VaAb8U.jpg] [image: 670%20-%20ZXNX5z9.jpg] [image: 431%20-%206T4S9rc.jpg] [image: 436%20-%20ki8usO2.jpg] [image: 443%20-%20KQFc9rT.jpg] [image: 448%20-%208e7jO7A.jpg] [image: 654%20-%20h0ikXj9.jpg] [image: 659%20-%20S0pJ0sx.jpg] [image: 664%20-%20QGnbxWG%20-%20Cagiva%20Raptor%20125.jpg]