DT125R FORUM

@DTGREENLANER I'd say that's a dry bearing inside the servo somewhere, I think they can be taken apart and the gear train serviced. Never done one myself but it's pretty much a scaled-up RC car servo, just take your time and lay everything out in the order you removed it and you should be all good. Southeast Asia is full of DTRs, DT230 Lanzas etc. and some of those guys repair the servos quite often.

Well, the Mito engine is highly strung. The Mito runs rings around the DTR, but as a result they're a lot more fragile. I had the same thing with my ETX, absolutely battered bike, but it's in such a low state of tune that the engine was crisp, almost criminal to rebuild it.

Yeah, I used a Honda CR85 Apico one on mine. I though the YZ 125 ones didn't fit.

Yes please @rallyfinnen I'll be watching this intently Always wanted a Lanza personally. Will love watching this progress.

@HOTSHOT-III thanks

Not familiar with a 1994 DT175 (I presume this is from the Asia (Far East) market). The oil light will just be for the two stroke. There are no sensors that do gearbox, the most you get is a Neutral Light sensor (if you're lucky). For the gearbox oil, the only sensors you see are with your eye balls and the oil sight glass. I can't 100% say this is the case, but I say it with high confidence that this will be the case. Hopefully that's useful. Calum

Well it looks like I have found the issue... somewhere along the line someone has pikey bodged the front axle and spacers... What should have had the sleeve spacer which has the 1mm wall which slides in to the 17mm ID bearing was clearly lost and someone had inserted a 40mm x 15mm bearing and used a spacer from an older DT in place of the correct one.. The joys of owning an unknown modified bike! So I am now getting a spacer machined up and I should be good to go! It has only been holding me up since before christmas.. so now I can get the wheels fitted, get the bike back to mine and do the final few bits before MOT.. starting to get excited now Picture of the spacer that I should have had below: [image: 1773302928622-spacer.jpg] Versus the spacer that someone had installed and was somehow using.. [image: 1773303198579-shaft.jpg]

Yeah that sounds like a good idea and should be easy to swap the wheels over without too much faff!

Hi, thanks again for the detailed reply and for all the information. I had already heard about the larger snorkel from the DT200/DT230, but I’ve seen that they are very difficult to find. Designing one in CAD could be possible, but I don’t have any experience with CAD programs and I also don’t have access to a 3D printer. Regarding the carbon reeds, I had heard about them before but I’m not sure which ones would be a good option at a reasonable price. I’ve also read that some people install a VForce4 reed block for the Yamaha Blaster on the DT125 with small modifications. However, it’s quite expensive. I did find a cheap copy on AliExpress, but I’m worried that the lower quality materials could damage the engine or even perform worse than the original reed block. The air filter was replaced a few months ago with a TwinAir filter, and the exhaust was also cleaned a few months ago. If I eventually decide to modify those spigots in the inlet port, do you know where I could find a good guide or tutorial to follow?

Cheers @beng1968 . I must admit, I bought 2 more Athena kits sometime after this post was made and can't concur with the opinions here. The casting was spot on and it was very good value for money. Considering it comes with everything you'd need to bolt it onto your engine, I'd say it's good value. I will agree it's not YZ rip roaring performance from stock, and considering the extent of tuning on my DTR, it's still nothing compared to a stock Aprilia RS 125. However, it's not without its merits. The extra CCs give a nice broader range of power, which as I've gotten older I've come to appreciate more (I'm no longer 75kgs wet ). I did take my cylinder to Mick Abbey for further porting and there is still more porting work that I need to do on my setup. It should be a decent bit of kit, when setup properly. The first experience I had was when I loaned my brothers 2001 DTR back in 2010, he'd fitted the Athena kit amongst various other mods, and that went very well. At the time, I went all in on a ported 3MB00P cylinder from the TZR Belgarda and that setup definitely served me well. I haven't been on my DTR for several years now and I am eager to fire it up again to rejudge my opinion.

Hello @chalcosoma, Apologise I didn't get around to replying last night. You can get away with running some pretty aggressive tyres on the stock rims, my friend once went very savage on his DTR (to the point spokes to breaking left right and center ). Sadly, I am not that clued up on tyres and availability in the States in general, but I certainly would have thought this wouldn't be a hard problem to solve. It would be interesting to hear what other people have run in the past as I know quite a few members had TDRs.

@Kristóf said in POS mode on switch: So does this mean that with the main switch to ON and the lights switch to POS it should light up the auxiliary light even with the engine off? No, lights switch to POS with the main switch to ON only illuminates the auxiliary light/tail light with the engine running because with the switches in these positions, the auxiliary and tail light receive an AC feed from the stator via the yellow/red wire. @Kristóf said in POS mode on switch: I'm asking this because my auxiliary light works when the main switch is to PARK but it doesn't work with the lights switch to POS Yes, this is because with the main switch in the PARK position, the auxiliary and tail lights receive a DC feed directly from the battery via the red wire (which connects to blue/red at the main switch in PARK). It took me a long time to fully understand this so glad I'm able to explain it properly!

After some research I did manage to find the sizes, and some more detailed photos so now I can actually buy some. I do think that it's rather a stopper or something than an adjustment tho obviously it changes the needle height, either way I'm sure they're important. Thank you all for the help!

Oh that's really cool! Well it looks well loved for, it's an appreciating classic that's for sure. I don't know of anyone who's done that conversion. The common one from back in the day were the Polysport conversions, but they're more enduro so not designed for peak brightness

Yes, the air leak will definitely not be helped by not plugging up the oil inlet on the manfild, albeit a tiny leak. Yes the '88 DTR ran the TMS26 carb not the TM28 carb found on all other years. That said, I am not aware of any other changes. So finding a suitable inlet manifold (probably can still be had new) and the airboot shouldn't be hard. But finding a genuine Mikuni 28mm is trickier. A split in the carb boot is not ideal, but it won't be the source of your problem. I'd just smear some silicone onto it and allow that to harden. Crank seals are common causes for air leaks, as well as the gasket on the inlet manifolds (once you sort the oil connector out). Spray some WD40 around the general vicinity and if the revs drop back to normal then you've found your culprit .

@Rat80y The drain bolt stretching is a common thing on the DTR, IMO it's a design feature as if you overtighten it it usually snaps. Whilst being a right PITA to get the clutch cover off and wind out the broken part, it does mean the thread in the crankcase is saved (new crankcases = much more difficult/expensive than taking off an engine cover) so I hope you've ordered genuine from Fowlers (get a load of copper washers as well for future gearbox oil changes). Tightening torque is 15Nm so it's also well worth getting yourself a 1/4" drive torque wrench like this one: https://planetx.co.uk/products/jobsworth-pro-torque-wrench-set-1 There is some truth in both your AI source and what your friend said. In the days of the 12bhp learner restriction, DTRs with the powervalve pinned shut would struggle to rev beyond 6k rpm but properly set up/derestricted/full power it should rev to around 10k.

Glad to have give it a once over Bent oil sump bolt

I use the Athena pipe with the 170 cylinder, it works quite well, and most of the power is in the midrange, even if I can get it to rev higher with modified ignition curve, the torque is in the midrange. I have seen Mick Abbey writing somewhere that the stinger ID needs to be at least 22mm (or was it 23) with the 170 kit, so that is a bit tight at least with the Athena pipe. The black paint seems to hold up quite well on the Athena-branded version.