DT125R FORUM

Hi guys, sorry for the really late reply, there was an unbelievable difference from changing the pipe and upsetting my main to 250, the bike pulls very strong through low end and has a big kick at high revs, it also absolutely screams way higher than my old stock expansion chamber with dep end can. Here's a video I took a while ago of a quick acceleration with the pipe, although it doesn't have quite the kick it has now that I've put my boost bottle back on, I had it off for a while to see if there was a power change.
The overall speed and power of the bike is about the same as my mates 2016 CRF 250x, both accelerate about the same and top out roughly the same, but the Dt suspension isn't quite as good
https://youtu.be/KQQ217FyGFE

Merry Christmas to everyone here, hope you all get The bike parts you asked for from Santa
I heard he would be doing the rounds Abit quicker this year

Bonus points for Christmas related bike pics

Went out for a solid 10 minutes to warm the bike up and check headlight wiring was correct, wasn't up for breaking an arm today

Hopefully it worked this time

It's been a while, again
But my DT is finally out of hibernation properly and I've done some little bits, passed her MOT the other week with a couple advisories, but nothing major at all.
Over the winter I've been fitting and experimenting with a new Polini PWK 32mm carburetor, after lots and lots of tuning and jetting I've finally got her right, not perfect, but right for now!
The carburetor made a nice difference I found, revs up clean and seems to have more torque throughout the revs than standard, fit original intake system nice too.
I bought a cheap blowtorch, butane and some heat proof lacquer to blue the welds on my romeu exhaust and clean up some of the rough spots from the grit and grime of the UKs winter roads.
It took a long long time and nearly killed me with the fumes but it's looking good now! And I'm starting to be happy with the build, still after some decals for the bike but struggling to find someone who can do designs how I'd like, but I'll keep the search up.
I also just got an absolute bargain of a DTR engine, I think it's a 2003 but it is completely unsplit, none of the bolts had been touched (until I got to it ) and it came with a fresh original carb and servo. Took the cylinder off to free the rings, piston and bore look brilliant but rings are slightly out of spec at 19 thou so ordered an original set and Athena gaskets to bring it up to spec. This engine will be dropped in my bike over the next couple months, just got to steal the unrestricted head from my current engine and it should be good to drop in once built.
Got a 200 mile memorial run in a week and a half so trying to get some miles on the bike and iron out all carb issues etc, I'll keep updated on how it all goes.
Here's a pic of the toys currently

I love my romeu hendriques pipe, the bike revs very happy, but I wont say anything else as it always seems to cause controversy with dep fanboys in DT groups haha

@Calum the ride homes a lot nicer than the ride there, even in summer 6-7am is cold at 60mph

@calum my DT must spend a lot of time in reverse, went from 18k to 14k in a year

Alot of enduros are registered under power from factory, they can be riden on A2 however if police decide to Dyno you it can cause issues. My mates Beta 300rr came brand new registered at something like 11kw, and I have seen alot of the KTMs are the same. Some insurers ask for proof of restrictions with a2 bikes, most don't. It's on you wether you want to risk it or not, however the likelyhood, atleast in the UK, of being convicted seems fairly slim, I know alot of people riding 600s, KTM 690 unrestricted etc on A2 with no issues, but in the event of a crash you may not be paid out, but the same goes for not declaring modifications. Insurance nowerdays is a nightmare, it's up to you how you want to go about it all.

@dylandt219 Calum’s right I’m afraid, carburettor is not the issue..
I’ve played around with the ignition timing through Ignitech DCCDIP2 aswell as carburettor and all sorts on my DT through the years. I recommend you work through what you’ve done and find the actual issue or limitation that’s holding the bike back, as even the standard 28mm can quite easily produce numbers on a mild ported 170 kit. If you’ve been messing with your timing through the zeeltronic put it back to a base map, fresh spark plug and check the spark is good, these units have had issues in the past and it’s not unknown for them to be duff out the factory. I would be more inclined to suggest an exhaust issue or timing related/spark problem than anything else, or if you’re still using the servo powered YPVS make sure you’ve not got it running backwards!
The carburettor should not be an issue unless you have jetted it absolutely wrong, but I think if that was the case you’d be having terrible running conditions all the time.

Hello all, it’s been a while since I posted
Just got the dt back out after a long time sitting, poor compression about 150 miles after rebuild with my new DTR bottom end and 3mb head and barrel with wossner piston, glazed bore so honed it and shaved my cylinder head down from a whopping 1.5 ish mm squish band to 0.9mm. Just run it in but been having issues with bogging out at higher revs and my ignition maps on ignitech. Long story short I’ve sorted out my float issues and jetting with Polini 32mm carb, that’s all good, and I’ve got good compression and squish band now. But I’ve been experimenting with ignition maps based off what I can find off old threads and research through varius forums, my ignitech ignition was a universal DCDIP2 so I had to splice into my loom and in turn had no basemap for the DT... I never got a reply off ignitech direct so couldn’t get a one ready made. I have a few maps that I think are in ballpark, ones near a standard curve which runs well but I’m looking to push this bike and make good power, I don’t commute and it’s a toy I’ve owned since I was 17 so I’m not all that worried about reliability. I experimented with a tune based off a 4DL race bike, the owner had been dyno testing and made somewhere around 28hp. I used some data off his curve and retarded it slightly where I thought it was a little advanced and then went for a ride. The bike was a completely different beast, for a short while... then I had some issues and basically in the higher gears it’s not wanting to push past 120-130kmh, it falls flat on its face like it’s losing fuel, but I’m sure it isn’t as I’ve got my carburettor issues all sorted out and with my regular slightly advanced stock tune I can push well past and off the clock zero issues. The bike has also melted a couple plugs after short pulls with this 4DL based tune (BR8ES)
I’ve ordered some BR9ES plugs but I’m back on my nearly stock tune now, I’ll post screenshots of the maps shortly when I’m on my PC, but I’m just wondering if any of you few Zeeltronic or Ignitech users out there have some good ignition maps that you wouldn’t mind sharing, I thought by creating this post we can share abit of knowledge to help someone in the future who might be having the same issues as me to come to a solution. I obviously have a lot to learn on this subject but I’m really struggling for base material on the original curves and how far these engines can be pushed, for reference my current modifications are a Polini Pwk 32mm carb, cut air box lid, slightly smoothed port where they transfer in crankcase, carbon fibre reeds, 3mb head @ 0.9mm squish, DTR bottom end (1998?) Romeu hendriques exhaust system. Thanks in advance and anything I find I’ll add into here later, but I don’t wanna share potentially dangerous maps and cause anyone else to have the same issues haha

Hi everyone, thought id finally make a thread for my build
Basically towards the end of last year I decided it was time to strip my DT down and rebuild it, sorting out all the shocking wiring and mess the previous "builder" had left.
Just before I stripped the bike down it looked like this

I had been wanting to do a USD fork conversion for a while, and a WR 426 came up on facebook for breaking, so I quickly snapped up the forks and front brake for a good price. I then went and bought a front axle and triple clamps for the forks and got myself a set of RFX bearings to match. I finally got round to striping the front end off the bike early this year and made my spacers following the bearing cup guide on here, worked a treat but I had to add an extra spacer at the bottom bearing and make a 1mm bush for the outer bottom race to fit in the standard headstock. Once the triples were painted and fitted it looked a treat, alot bigger than the standard triples and forks!

I then cleaned up, primed and painted my forks, fitting some fork sleeved to keep them protected, also fitted some grips and mounted some bits on the bars.

Notice the MT 125 wheel in the rear, I had bought and planned to fit these wheels to my DT as they were a cheap option, but the manufacturing needed for them to work would of been very tricky, I made an axle first which worked good, but the rear wheel even when spaced correctly would need a hubcentric spacer for the disc and spacers for the sprocket. The axle was also very thin compared to the standard DT rear axle, long story short I scrapped the idea as I just wasnt happy with how safe the bike would be after all the work, mainly the tiny mt rear axle. Once some DTX hubs laced to saxess rims with stainless spokes came up for £100 I snapped them up.
While waiting for my wheels to arrive I sanded and polished my tank which I resprayed in 2k gloss black last year, also fitted the seat on the bike

I made a custom front axle along with bushing for the DTX front wheel to work in the huge forks, spacers were nearly perfect on standard rim and only needed slight modification, I also got to keep the speedo drive and standard clocks which was a big plus for my budget.
I made the axle out of 30mm EN8 bright steel, worked great but was tricky to turn down. The end was threaded in M14 x 1.5 like the standard DT front axle and a stainless nylock nut used.

Rear wheel fitted with standard axle as youd imagine, fitted new pads front and rear aswell, sadly the rear caliper pins had corroded a little so the slider wouldnt go far back enough for the disc to be free, after some grease and persuasion it went and the brakes free.

Got the bike out today as it was fairly dry, alot easier to see any marks or rough spots when in sunlight.

Overall im very happy with how the builds going, ive definitely missed alot of work that ive done but will try keep the thread updated as I go along. Ive got the caliper adapter to make along with other things like the headlight etc, but the bikes been fully serviced and should be good for its mot next month, new chain, sprockets, oil, pads and good tyres. This summers going to be a good one.

Cheers
Glynn

It really isn't much to look at! Inside and outside
Looks like waters been in the crankcase also, casings are benign split tomorrow hopefully and looking at possibly bead blasting the crank if I don't find a replacement, gaskets and piston are ordered.
https://i.imgur.com/tsqKxNp
https://i.imgur.com/jL4HXks
https://i.imgur.com/vg2zHgF

EDIT
Will embed images later I don't have my PC atm and phones not liking imgur right now

DTX wheel hubs are slightly different, the disc side wheel spacer is different so you'll need that, then it should fit on with speedo drive. You'll need to make a caliper bracket though and I'd imagine you'd find the standard DTR forks abit soft.

Had good results with my Polini PWK 32, fits standard airbox and intake without mods, jetting was a bastard and I spent alot of money on jets and needles, but at least now I have a very good base point for someone with a lightly modded DTR to work from.

Got the carburetor on nicely yesterday, with heat the airbox went on well, cheers Calum!
Cutout the lid of my airbox completely and fitted a new air filter, it was butchered anyways.
Upon first start the caburetor was obviously way lean, would only run on choke and it sounded crackely, so swiftly shut it off and fitted one of the mid range pilots I had and removed the main jet, as to your guide Calum.
Bike ran nice, could adjust the pilot circuit nice and it seemed to have a sweet spot with the screw fairly far out. Bike would splutter badly when going full throttle, obviously due to the main jet being removed, but up to 3/4 seemed to rev nice so didn't touch the needle yet. Fitted the 142 main jet out of my kit, which was alot bigger than standard, think the second size up from my kit, bike ran nicely up to temperature on the spot, revved fairly clean but has a bog when pulling throttle wide open from idle, I know this is likely the main jet being lean but I didn't want to change it until I have the needle and pilot correct.
Went for a 5 mile run into town for some petrol, bike splutters and ran crackely up to about quarter throttle when riding the bike at a constant rpm, seemed to smooth out past that, so I'm guessing pilot is still lean?
However it also had similar symptoms while accelerating until higher rpms, once onto the main and the ypvs opened the bike went awesome, bags of power and sounded very crisp, however i didn't ring it out too much. Temperatures are staying good while riding.
I'm thinking tomorrow I will raise the needle a notch and swap out to the next size up pilot jet and try another test ride, I've got the next couple days off work to play about with this, and this carb is brilliant to work on.

Ive been off this forum for a good few months now but I went through a lot of tuning with a Polini PWK 32mm on my DTRE. On standard engine it took a lot of jetting and needle changes to find one that worked but when it was done it had a little more torque than stock. I had plans in the pipeline for a new engine build and programmable ignition which is why I changed the carb, my engine was worn out when I tried it at first but it does work and go well, you'll need to adapt your throttle cable. I have now built my new engine up with ignitech ignition and advanced map, carbon reeds etc and it needs rejected but goes very well, unfortunately I haven't had the time or enthusiasm to go on any bikes since spring last year but if I get round to it this year I will finish tuning the DT and write more on here, I have wrote some stuff about the polini carb on here before, I'm not sure if you seen it or not.

If anyone finds a good company for producing stickers I'd happily put an order in for a few, if we all pre ordered before the distributer puts an order in they would not end up out of pocket.

Thanks so much Calum, doing a wr426 fork conversion right now and was having a hard time with it.

@NINJA crikey, think it's time to scrap my winter tuning project and get it sold