De-restricting a DT 125 1994



  • Morning,

    Been looking into it on the net but seeing different things every time.

    Could someone tell me all/most of the different restrictions on a 1994 DT 125?

    Any help is much appreciated!



  • @JonathanLuca I don't think that there's many restrictions on the older1994 model to be honest! It was mainly the later years that where restricted. If you haven't already then I recommend buying and installing a full new exhaust system and afterwards going up a bigger size on the main jet and you should see a performance increase .. You could also trying playing around with the gearing/sprocket set up if you need more top end or for it to be quicker off the mark but above and beyond that it's pretty pointless ! Another idea is to buy a different CDI there's a few members on here running zeeltronic CDI units and similar and have said it's probably the best upgrade for these bike so another option 🙂



  • Reed switch de-restriction is the main restrictor here.

    Add a Full Dep exhaust swap, 13-55T sprockets,

    Be done with it, for these older series DT125Rs it's all go already.,



  • @Darty what do you mean by reed switch? Sorry if it's a silly question, just starting to cut my teeth on these bikes. I have a dep tail pipe so far so will be getting the downpipe asap.



  • @JonathanLuca it's in the back of the Rev counter, have a look online to find a picture of it so you know what you're looking at.

    Don't disconnect it or cut any wires though, just wrap some electrical tape round it and tuck it away, making sure it's protected from the glass part breaking.

    The switch turns on once the bike is past a certain rpm and speed, stopping it from going any faster than a certain speed, from what I can remember!



  • @Burridge excellent cheers mate, I'll have a look at that tonight. Still trying to get the bugger to run right. Appreciate it!


  • Global Moderator

    I was always under the impression that the main factory restriction on the newer models, was a wire that is fed into the back of the speedo but NOT connected. In order to get the power valve to function fully, allowing for a much higher rpm, you had to GROUND this wire by connected it to the frame, or another ground wire somehow. I also thought that the older models didn't even have this restriction in place?



  • @MIGHTYMAN said in De-restricting a DT 125 1994:

    I was always under the impression that the main factory restriction on the newer models, was a wire that is fed into the back of the speedo but NOT connected. In order to get the power valve to function fully, allowing for a much higher rpm, you had to GROUND this wire by connected it to the frame, or another ground wire somehow. I also thought that the older models didn't even have this restriction in place?
    Yeah the older models don't, mines a '99 and it didn't have it so I'm guessing it was the 2000 and over models that did, Callum will know haha!



  • @MIGHTYMAN That was a restriction on the RE models. To be honest the RE's always seemed simpler to derestrict.

    The obvious ones were the exhaust pipe, YAIS (not convinced that's performance lol), Green Black Wire powervalve.

    Older Models were reed switch, some had restrictive pipes,


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