DT125R FORUM

@4rw1n92 looks just like a regular DTR, a picture of the bike would be better help.
On another note I’d maybe delete those pictures as you’ve just given the internet all the individual codes for your frame and engine, so that could easily be re stamped on a stolen bike.

Cut the lid off and send it

@stevie-wonder I’ve had his MX style pipe on my RE for years, and I think even that I bought used, it’s awesome and took some abuse/dents over the years. That’s a sad ending to it all but can’t blame him, it’s bad enough trying to post items that big across the UK alone.

@louis-dt-wr I wish they had these back when I was doing my DT, OEM was expensiveeeee

@karumaspt I had this problem with my DTX SM wheels when I fitted USD forks. I’m almost certain you cannot get a 320mm disc with the same stud pattern and PCD as the DT hub unfortunately, the biggest I could find was the DTX/WRX disc which is 300mm if I remember right. You’ll have to make your own calliper spacer aswell as I don’t think anybody makes them off the shelf for this platform, but there is a drawing with dimensions that used to float around the forums and it’s not too difficult to make.

For reference I’m running about 1mm squish on my engine with programmable ignition, I was melting the tip of the standard range spark plug after a top gear hoon but I think I was a fair bit further advanced than standard on the top end, I’d maybe stick to 1.2-1.3mm, I’m sure that’s the standard figure but my Frankenstein engine with different barrel and head measured something crazy like 1.8mm as it was! So it’s worth checking..
also to note for the future, you don’t want to go any less than about 0.8mm squish on these engines as the Conrod stretch at high rpm will smack the head.

@dylandt219 asking for advice and replying in the way you have is childish and just makes you look like a tool mate, if you clearly don’t understand what you are doing I think the best advice anyone can give you now is take the bike to a mechanic. Everyone here is trying to be helpful but it’s clear you’ve already chosen the route you want to go down, so why even ask?
You can take the advice or alternatively spend £200+ on a big carb and have an even bigger steaming pile of shite that still goes 100km/h, you’ll learn either way

@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.

@goprokid95 where abouts are you? Stator rewinding is a professional job and usually costs more than just buying a new part, companies such as electrical motor manufacturers do it. If you’re in the UK I have a good DTRE bottom end I could possible sell the stator off if I got the time to strip it.

@calum yeah I’d agree mate, even when I fitted and setup my 32mm I wasn’t all that convinced it made a huge difference, and massively reduced mpg haha. But ofcourse the benefits come with the other changes that were made, but if I’m honest the standard carb on these bikes is a cracker when it’s setup right.

A little off topic but what are you looking to achieve with a 38mm carb? It’s massively oversized for standard porting, I would be looking at more 30-32mm maximum

@Calum thanks Callum, yeah I’m sitting a bit more advanced than that but a similar curve, I’ll compare better later and update, but I’m at 14 degrees timing at around 10k rpm

@Calum if you get a spare minute that would be great cheers, I can’t seem to get the files off the zeel website, I downloaded the programmer but can’t load anything as need to plug a unit in by the looks of it. I’ve spent an hour or so adjusting my safe map to add abit of advance and try get abit more torque in the midrange for now, will see how this goes over the next few days and update this post, but yeah it would be great if I could compare against a professional such as zeel

@Calum oh great I’ll have a look for that, you wouldn’t remember at all which one you had best success with would you? Or are they all fairly close

@Calum the ignitech seems to work fine but I’ve had a couple little issues, it took ALOT of time to get it wired and actually doing something at the start, these are hard to diagnose faults aswell, I’m just a little lost with it all now and looking to possibly push some boundaries with a fairly budget setup, I’ve got someone local ready to do dyno sessions after lockdown. Even the standard ignition map details from a zeeltronic would give me a good start I think, I just need the degrees per 1000rpm or such. It’s very interesting how much of a difference small changes in timing affected mine, the 4DL based tune really ripped, I’m +1t front sprocket on sm wheels and it stood right up in first and second under acceleration, shame I can’t keep it from eating plugs haha

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

@Haako-Smith Mikuni jet sizes differ to Keihn etc and flow differently, 210-240 main jet is correct on the standard flat slide 28mm

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.

@Calum saved Abit of money with the ignitech and I'm really happy with the new software etc to be fair though, and the spark is terrific out the unit!

Jetting a none standard carb on a DT is a ballache, 32mm polini pwk didn't make my DT much faster at all without any supporting mods like ignition etc. The fuel usage was well over double too even with both carbs appropriately jetted.