Dt125x engine in a dt125r frame ?



  • Hi guys I'm new here I have purchased a yamaha dt125r 2002 model and after a topend rebuild I have worn it in and now covered around 2-2.5k miles and now I can feel grinding in my footpegs and have a horrible rattle on deceleration pretty certain it's the big end bearing on the con rod I have been offered a dt125x engine in mint condition for a good price and I'm wondering will it fit into my dt125r frame and work not bothered about the electric start as I'm used to kick start now. I just need the headlights to work and the speedo I don't think the rev gauge will work because the dtx diddent have one I'm pretty sure.

    Any help will be appreciated.


  • Global Moderator

    @micheal-cox the DTX engine will fit in your frame and you will be able to use the rev counter if you take the rev gear out of your current engine and put it inside the DTX one, although considering the effort it will take to do that, you might as well just rebuild the bad engine. Before doing any of this though, you should work out why your current engine has gone wrong. If you let go of the throttle and use the engine braking a lot, you will starve your engine of two stroke oil potentially causing the issue you've mentioned.



  • @Mightyman thats how my big end bearing gone !



  • @Mightyman so if I was to put a dtx engine in my bike it would bolt up and work fine as the dtx engine is only £150 so is cheaper to put in my bike than fix the other engine as I don't have the first clue on how to do a crank rebuild and yes I use engine braking but I give it a little rev every now and then I never leave it more than about 5 seconds thanks for replying so quick 😊



  • @micheal-cox Well no, yes it'll fit. But that doesn't mean it's going to work.

    The electrics, hence E, are completely different bud.

    The flywheels are different, the generator is different.

    It's going to cost you more than £150 to get the RE working on an R.

    Just rebuild your engine.

    Crank rebuild is a specialist job, Yamaha Skellerns Cheltenham did mine for £30. PJME also offer this service.



  • @Calum ok thanks for the advice I'll just rebuild mine as I don't want to change the electircs over 😊



  • I have a Dt125re engine in my DTR 🙂 just electrics and tachometer cable need converting also did the kick-start conversion 🙂


Log in to reply