DT125R FORUM

@Koltin As far as I know all pre-DTRE master cylinders are the same from 1988 until around 2004 so I'd start by comparing part numbers on Fowlers website, look up the part for say an '88, a '96 and your own bike:

https://www.fowlersparts.co.uk/?gad_source=1&gclid=CjwKCAjwl6-3BhBWEiwApN6_ks8FnxkMK8pUTlwAmDTt4wZ4GV5FlSqAj_zeubTOZF-qK69xd1CwVxoCpO4QAvD_BwE

Power on this run was 16.98 bhp.
On other runs it was 17.58. Without any mods.

Maybe it's from the 3ET DT200R,has the same carb as the DT125R but uses different numbering in jets, the main is 150 but is not smaller than the 210 of the DT125R.

I hoon around town on an unrestricted DTR and it uses less than 5 L/100 km.

Hello, I'm Paolo from Italy. I have a DT 125 red with grey frame. Do you know the RAL color of frame? Thanks!

No pics yet been busy though got a new motor for it managed to get it all in and running but got a strange problem ive put an orig air box on it and it wont idle I have to turn the air screw all the way in otherwise it takes a little time to down rev but then if I turn the screw to the 1 5/8s its supposed to be at or any where from seated its bogs out when you rev and has erratic idle takes ages to settle and cant decide what it wants to do even with 4 or 5 screws of the idle screw in out out it doesnt make much difference to idle speed.

So I am a bit stumped other than changing the coil pack and cdi as it went through plugs before and is now still doing something similar was fine on an 8 then it decided it didnt like that plug stalled and refused to start then did the same with another 8 I found a 7 and it starts and goes like stink when riding did 30mph up my steep hill testing it but its got that idle prob.

So i'm going to get some new plugs try and get funds for a coil and cdi maybe a new regulator as the voltage its a lil strange charges about 13.3 on idle to start off then after a few mins only sits at around 12.5 unless you rev crap out of it it will then go to 14.4

All fun and games any ideas welcome for me to test next time I get out to it would be appreciated. Trying to be careful and cycle it with the new piston so it beds in ok already got a strange rattle not sure if its just a bad bore settling in or a loose bit of old piston ring dancing around the crank but its whats going on with me and this lil ped for now thought ide send a quick update n ask a few questions from you seasoned vets.

Good that you've confirmed that it's not the powervalve, that's one thing we can rule out.

First things first, bin off that coil. Get yourself a genuine 3RM one.

https://www.fowlersparts.co.uk/parts/view/4RP8231026

I had a horrendous issue that took me months to diagnose, since it would run absolutely fine from cold-warm. But after a short while it just refused to rev. It took me literally forever to figure out, I swapped loads of bits out and considering my bike was a "fresh" rebuild I didn't think it would be the "Racing Coil" I bought. It hit me when my brother was having problems with his RD I noticed he had the same type of coil and the tuner said bin that immediately and all his problems went away!

So first things first, get yourself a genuine coil.

Later coils are a different part number:
https://www.fowlersparts.co.uk/parts/view/3KJ8231013

So it might be that your coil isn't right for your bike/year. So just source the correct year/model coil for your bike and make sure it's a genuine one (Denso I believe makes them).

Secondly, I've seen this before whereby the exhaust got full of water after a DTR was stood outside for a long period of time and this had very similar behaviour. Running rich and lacking the ability to rev/pull hard.

So whip that exhaust off and give it a good clean, it was very odd and not something I had considered.

Later model DTs were fitted 210 main jet, but again this all depends on your carb that you're running and whether or not you're fitting genuine Mikuni Jets. Ideally you want to be fitting the right jet for the year/ignition etc.

@Calum Sorry to hear about your car bud. +1 for I'd keep hold of those extra clutch cover inserts if I were you, they look ace and are a part that can get rubbed/scratched just from riding so it would be cool to be able to just bung on a fresh one as and when.

Frame looks same bottom end on tht looks like the dtr engine I have my 4hw has no cover over the oil pump and has some kind of make shift bracket for the oil cable. Looks like they chopped my frame and put a heavy duty swingarm on for that 4DL raised the coolant tank and put bat under the seat. Thats why I asked cause surely the 4 wires from the engine are the same or do I have to change the flywheel coil bit of forget its name now. I think i'll give it a bash as I got to remove the engine anyway if the mountings are the same and it wires up maybe I can put a DT rear sprocket on.

Food for thought ive got to get the energy to get at it first i'll look over that cdi wiring diagrams thing you shared and go from there just hope the exhaust mounts dont throw it out of whack.

I'm hands on so once got all the parts in sight i'll hopefully make sense of it all feel free to leave suggestions etc like I said before wish I had someone here to help me out going to be fun though so hopefully will give me more incentive.

@dominik22 Well you're doing better than me, once I was rebuilding a TDR250, thought I'd finished and then rode to my friend's house without connecting one of the carb warmer hoses! As you can imagine the temp gauge skyrocketed, luckily it wasn't far and we were able to top it up so I could get home.

Hey,
can someone tell me which springs fit in the wr 200 fork? I ride this bike with Supermoto rims.
So im looking for stiffer springs..
Greetings from Germany

Getting there...

I am pretty happy with the design, I just need to modify where the holes go as there is that gap at the bottom I want to close up. It may just be easier to drill the holes myself.

I've got a quick print going now and I'll drill the holes myself and then remeasure it and do one final print. If that still comes out wrong then I'll just drill the hole myself.

Ideally it would all be part of the CAD so at least if, for whatever reason, I need another one, then it would be simple enough to sort out.

New rear disc ordered as mine is warped. Need a fresh set of tyres on this rude boy too. These are coming up for 10 years old now...wow 10 years 😮 scary to think.

Motul motocool expert (yellow) and Aisin coolant for motorcycles (blue)
I prefer Motul because it's the best I tried,has the least fluctuations in the temp during usage.A little expensive 10 euros per liter.Normal riding city or cruising 65-75c temp,on the high side 87-90c when going up the mountain through steep bad fire roads.
Second one is the Aisin,similar performance, normal riding city or cruising 65-79c and up to 95c on the fire roads.5L for 21 euros.
All these on Greek hot summer evenings,34-38c.
Currently filled with Aisin because I had 3 liters left and doing some work on the bike.

Also got me thinking about that high mileage bike you had maybe it had a slightly diff sprocket setup or something or just a blessed engine my current one pulls so nice with a larger front sprocket I took the Keeway out for a test drive today and man its slow af compared to my DT rid it like a 2t lol trying to get it warmed up but rekon it only hit 40 max on my street my DT would happily hit 60 here hehe can't wait to get her mot'd but really itching to get the TZR running right and having a proper go of her before I decide to keep or part with her do really want the hat trick with a 90s TDR as well though a French import like you had would be the icing tbh

I already ordered what I thought was a full set and everything else is the right colour but the cowl was listed as blue instead of sky blue, it looked the right colour in the picture but it was taken in a shadow so was hard to tell and when it has arrived it doesn't match any yamaha colours, not sky blue, not endurance blue and not deep purpleish metallic blue so now I'm trying to sort it out with them but looking for a genuine one incase they can't get one

Hi did you get sorted out I’ve got the same engine any my loom is intact it’s an import from Europe slightly different to uk model these have a reed switch for restrictor in the headlight

You know thats not a bad idea i made up some gaskets that held and some stuff for a workbench and some pc feet that still hold up cant remember the name of tht printing material but had a nice spongy bounce wonder how well it would take up with the seasons though outside. What came to mind was one of them old girvin flex stem elastimers we used to have in the 90s on our mtbs but bet you cant source them either nowadays just hoping I dont ruin the bushes n stuff when I remove it still in two minds to do the front tyre and get tht mot n prey he dont notice it not as if im going to be doing jumps off road on it now theres nowhere left to ride round here. You got me thinking now though if I can stretch the spring enough and tht printing stuff holds enough for me to slip a rubber printed collar around the shaft happy days.

Your more than welcome to come and help me though bro just been reading them blog posts about couple of them builds tht RS n Yamito you got some mad skills n patience would love to restore one of mine and rebuild the engines properly i'm to impatient to rebuild the cvt on her moped lol

Thanks lads appreciate tht will see what I can do with all my old parts hopefully get this old girl growling like she should