@Calum said: You can measure the coil to see if it's within tolerance, what I was finding was that from cold it would work a treat, but once under load and warmed up, it would fail to fire above 4k RPM. Okay good to know. So even my measurements looks okay to me I thought about that it might not be okay under load anymore. But I didn't want to manipulate any plugs just to measure under load. @Calum said: I've had this before with a faulty ignition coil. These can still be bought brand new from Yamaha and I highly recommend going for genuine coil over an aftermarket one. The aftermarket one I had led me on a wild goose chase trying to figure out the intermittent faul Do you have any link or shop? Thanks

Update: it now works, adjusted the timing a bit. Helped and do not know why it worked now since ive tried before and upto no progress then. It idles decent but it only runs nice with the choke on. Without choke on it runs like ass. Ive just fixed all the intake manifold gaskets and made it way better so no airleak. Changed the crankshaft seal and that also should be very very minimal. Not sure where else it could leak air

They say it's mechanical but the description sounds electrical and they're adamant it's not I still maintain it's electrical related, ignition timing, static angle, etc. But I am not familiar with the ignition system they're running and/or how it's been wired together

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

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]

Could be a lot of things.. but everything is probably not as it should be if it's not starting.. What I can think of: -Leaky crank seals -Damaged/leaking reed/intake -Carb issue -Ignition angle off (flywheel key?) Is the spark plug wet? Is there a good suction pulse from the carb when kicking it? With some experience you can feel it if you cover the carb with your hand on full throttle while kicking/cranking the engine. It should not blow, only suck, and the pulse should be 'strong enough'. Old fuel can make it hard to start too.

@Calum @raceraidan Interesting thread. I once owned a 1998 DT125RE French import which looked identical to a DT125R the same year (pic 1). It had a larger battery and separate toolikt compartment as well as the electric start wiring. [image: 52481614948_a84fb86893_b.jpg] During this time I was fortunate enough to source a Yamaha service manual for this exact model, I still have this and here are some pictures of the wiring diagram. I believe KTM also used this engine/electrical platform for the LC2 125 which they sold a lot of in Germany (I bought 2 or 3 3MB CDI units marked LC2 125 from German breakers, and also some NIP 3MB YPVS servos which had both the Yamaha and KTM part numbers on the packaging (sadly now all sold). During my ownership I tried all these items on the bike and they all just plugged into the loom (same connectors) and worked. I'm pretty certain the (inverted) flywheel and stator were both stamped 3MB. As you can see this model also has a clutch switch which IIRC, with the clutch pulled in, allows you to start the engine in gear even with the sidestand down, but cuts the ignition when you let out the clutch to try and pull away. If you've already looked at the sidestand switch I'd locate this and give it a dose of WD40 etc. as a starting point. Also the two relays (items 12 and 13) are worth a look although I'm not sure how you'd go about testing these. It might be of some help to just get some more and plug them in and try them. Here's a link to the KTM parts fiche; search Google/eBay etc. for the KTM part numbers as well as Yamaha France and you might get lucky with a European breaker as they can be quite diligent with posting up used parts for sale including the original numbers: https://www.trevorpopemotorcycles.co.uk/index.php?main_page=ktm_fiche_finder https://ypec-sss.yamaha-motor.co.jp/ypec/ypec/b2c/html5/app/en_GB/parts-search/index.html?ver=bd30d8f2-88bf-45bf-81ba-b46167a61f3c Here are some pics of the wiring diagram, not sure if the Gilera SC125 used the same electrical platform but hope this helps: [image: 53464155671_38fb444afb_b.jpg] [image: 53463243007_9a4dea8951_b.jpg] [image: 53464293058_21dae26cab_b.jpg]

https://dt125r.co.uk/topic/13/kick-start-conversion-dtre

Yeah looks like it's in need of some TLC. When the bikes in neutral all the lights should be on. As I say, that bike looks like it's got a lot of issues and working through those by restoring it to factory is what I'd do.

I see you also recomended me the Zeeltronic. I'll make some research about it. The main problem for this bike at least in Spain (where I'm from) is that there's not really any market for it, and it's a shame really. I saw the carburetor as the "accesible small powering piece". I just dont want to change the cylinder or big things like that, just a small thing to change the performance of the bike without going for too much, just a little push. If Mikuni is good brand then i'll search for a 32 Mikuni to keep the line of being always equiped with Mikuni. I bought the bike with a Gianelli exhaust with homologation. I see almost every DT with installed Arrow, DEP, Turbokit or Gianelli exhausts kits. It's the only aftermarket thing installed to it. Now before changing carburetor or anything else, I need to fix the regulator, alternator and battery, and then i'll see. I see you're also pretty close with the bike, and very aknowledged about it. I really aprecciate the advice you're giving me.

How local are you to Dorset? Buy mine. Respoked/new bearings 2000 miles ago, nearly new tyres disc rotors and pads, ready to bolt straight in: https://www.ebay.co.uk/itm/266386635256

@Calum I think it was £45 but it must have been about 10 years ago. Not a DT either it was a vfr400r nc30 that stopped charging the battery. They must know their stuff about motorcycle stators as I found the advert in the back of MCN. Also they claim to have most models on the shelf ready to exchange for quick turnaround.

Looks like I have the same stator set up I got a dtre engine missing the stator so I fitted the spare I had from what I believe is an old tzr125 it's the 3 coil one with the matching flywheel then took the spragg clutch off the back of the X flywheel and it's a direct fit onto the "tzr" flywheel

@350_2stroker PS they unscrew by turning clockwise...

@skunkno1 I am not going to comment. I run Silkolene Comp 2 Plus and have the same issue But I'm not bothered by it.

@declan I know, but the sight glass is problematic. I’ve seen posts where people thought the oil had disappeared but really had gone above the glass If my gear change feels smooth, I’ve got oil