DT125R FORUM

I agree @Calum , I will let you know if there is any news. Did you see the message above about the neutral relay?

@Calum Now that I look at it I don't know if it has anything to do with it, but I have a four-wire connector disconnected near the water tank in the back, apart from the one for the lights and indicators. I read that it is for the neutral relay but it doesn't have it, I have to attach a cable or something. Could it have something to do with that?

@Calum That's right, I already tried with and without a snorkel. without it works better in wot, although it still needed a little more, that's why I tried removing the yeis that is screwed to the frame. If we look at the problem with the naked eye it would suggest that I have a main jet that is too rich, however I checked its sizes including the pilot and they are fine, they correspond to the DTR model.

@Calum Oh well, I didn't know he also had the same name as the other one, good to know. On the other hand, if the motorcycle is original and not modified, why do you suggest that the problem could be in the airbox if it is in good condition? Or did I misunderstand what you mean?

@SpookDog @Calum Thanks again for the suggestions but let's go in parts, Jack said, I made sure the air filter was clean, then maybe I expressed myself wrong or it was the translator's fault, but I repeat, I didn't remove the yeis. I removed the black bottle that is bolted to the frame on the side and fits into the rubber that connects the air filter housing to the carburetor. That is, imagine the air entering in excess when opening that inlet and very little through the air filter box. The logical thing would be to think that it would work worse but it was when the bike worked better at least in wot and it did not have the damn failure despite the large excessive air intake, which makes me think that perhaps I still have an electrical fault that I have not yet detected and that would make a weak spark at high revolutions that is not powerful enough to burn the fuel in wot. I even tried with everything connected without the snorkel and although it improved it was still a little rich so imagine.

@Rallyfinnen Continuing with what was said, by giving it more air in this way the bike improved significantly. That's why I doubt and maybe a 210 plane is needed instead of 240. Maybe this is some kind of limitation? What really changes in the previous, more similar models to carry this model with larger aircraft? Or I have a weak spark at high rpm, so with a higher, leaner air ratio, the mixture reaches the rpm it should reach but probably with less power.

@Rallyfinnen Hello friend, it is not the yeis that disconnected. What I disconnected is a black bottle that goes on the side of the frame and is screwed into it. It connects to the rubber that joins the air filter box to the carburetor, I understand that not all models have it.

On my previous two-stroke, once the stator ignition coil went bad, when I installed a new but inferior one, the bike felt rich at high revs, so it tolerated/needed less fuel than before to run properly, although it translates to less power if the bike tolerates less gas. Something similar may be happening, although on this bike everything looks so healthy and with little use that I doubt it but I will have to check it again, maybe a ground cable? Sorry friends again for so much text and thank you for your time.

c@MadGyver Thanks for writing friend, it is the rectangular version where the pulley fits, it is well aligned and works correctly, at least as far as the pv is concerned.

@Calum Well I have news, I tried what you told me about disconnecting the PV after its cleaning cycle, however the problem persists. On the other hand, I connected the reed switch wanting to cause the limitation to remove it again (I know it doesn't make sense but I didn't know what to try). There were no changes either, but here's the surprise, since the symptom seems to be electrical but it is also confusing with a rich mixture at high speeds, I tried unplugging the black plastic bottle that is screwed to the frame on the left side and there the following happened, as expected, when leaving, especially at low rpm, it felt thin but to my surprise at high rpm it went to the red line (I had never done that) I did around 80mph at 10k, obviously air enters in excess and it does not make the best carburetion but without that plastic piece at least it suggests that the problem is not electrical. The question is the following, for the motorcycle model it carries 25 and 240 jets. Could it be a limitation intentionally that the bike is rich in highs so as not to deliver all the power and maybe it really would take 210? It is even strange that with the reed switch plugged in its original place it has made that speed or perhaps having the 3rm20 cdi such limitation does not work. What do you think about the jet? Have you read something similar? I never understood why some models have the same top end kit, exhaust and carburetor, but they still have different jets. Sorry if I wrote too much, I was excited to see a beam of light in the problem.

Thanks for the suggestions @Calum . Today I checked the battery connection again, I disconnected it, cleaned it with wd40, plugged it back in and to my surprise it is now worse, the same fault but around 8k. Will the CDI have any memory and when you disconnect the battery does it reset in a certain way? I'm going to try putting the reed switch back in its original spot, causing the limiting to work, and then removing it again. It doesn't have much science but the truth is that it drives me crazy. I haven't tried disconnecting the PV yet, I have it pending to rule it out. Although accelerating at wot and without the cover, seeing the pv pulley, it works fine.

I add that it has 3rm-20 cdi, 3mb00 cylinder and 3nb cylinder head. chassis code de031 and under the seat it says 3rmj-030. I also want to thank everyone for all the information shared on the forum that I read previously and it helps new owners like me a lot.

Hello people, I am facundo, sorry for my English, I am using a translator. I recently purchased a 2000 DT125R with about 21,000 miles. After a carburetor cleaning, I moved the reed switch aside and removed the two pieces from the inside of the exhaust. The problem is the following: the bike reaches the power band but it is short, it does not exceed 9.5k, it seems like an electrical cut but I have doubts if it is rich. Before submitting to the forum, I read everything I could find about the problem on different forums and looked through it, but no luck. I already replaced the spark plug, cap and Ht, I also did the side stand thing, I already measured the fuel level in the carburetor and it was within range, the PV is working correctly and I checked it. The battery is new and its connections are good. Original carburetor with its jets corresponding to the model, main jet 240 and pilot 25. I need help, where I am from there is no information and almost none of these motorcycles, any suggestion would be appreciated, greetings.