DT125R FORUM

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.

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

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.