@Calum yea the thing is that I have heard that the German version uses a diffrent cdi from other regions and I haven't found a guide on how to derestrict the cdi on a German one

Hey! I know I'm late but I have a 1988 Yamaha DT125R swiss edition, which has the 3DD code. I checked the parts diagram and the 3DD-14610 pipe is originally the 1988 swiss edition pipe, which is supposed to be heavily restricted. I'm pretty sure mine only has a catalytic converter, I was hesitating about cutting it open but now that I saw your pictures I think there's no reason to do so. Your pictures look like the pipe really only has a catalytic converter. But I must ask, were there any restriction cones or washers that you didn't take a picture of? Thanks!

Hi, thanks again for the detailed reply and for all the information. I had already heard about the larger snorkel from the DT200/DT230, but I’ve seen that they are very difficult to find. Designing one in CAD could be possible, but I don’t have any experience with CAD programs and I also don’t have access to a 3D printer. Regarding the carbon reeds, I had heard about them before but I’m not sure which ones would be a good option at a reasonable price. I’ve also read that some people install a VForce4 reed block for the Yamaha Blaster on the DT125 with small modifications. However, it’s quite expensive. I did find a cheap copy on AliExpress, but I’m worried that the lower quality materials could damage the engine or even perform worse than the original reed block. The air filter was replaced a few months ago with a TwinAir filter, and the exhaust was also cleaned a few months ago. If I eventually decide to modify those spigots in the inlet port, do you know where I could find a good guide or tutorial to follow?

@rich1299 said in Yamaha DT 125 R derestriction: Hi I’m looking at de restrictions on my 2007 dt 125 Could you possibly tell me what I can do to get more power Hi @rich1299, It's literally described in the last paragraph of the post I made. Zeeltronic ignition system gives a big boost to midrange DEP system also boost mid range VForce Reed block Bigger carb Athena 170 Kit Cylinder porting Head squish adjusting Lightened flyhweel Just to give you some ideas...

@HOTSHOT-III damn just did enduro on sunday and the bike shut off instantly its having electric problems im having a very weak spark the bike doesnt turn on at all tried bypassing the killswitch and the kickstand switch no result and now i want to check the pickup coil from the stator im not that good with electrics but im trying my best to find the problem

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

Quick answer since I have a 2002 as well (DE03): 1 - Swap expansion chamber (the blobby exhaust bit) to an Athena or something. This was the big thing. 2 - Pull out the reed switch from behind the speedometer. Do not disconnect it or cut any wires, just wrap it in tape and stuff it aside. It detects when the needle gets to ca 80 km/h and cuts ignition there. That should be it, your bike should now rev freely to 9500 rpm and do 120+ km/h. Also: ensure that the YPVS is working as it should. Remove the round cap on the left side and turn on ignition. It should rotate back and forth a little, then settle such that the groove on top is right over the hole. Explanation on that last bit: The YPVS switches the port timing between low revs (more torque) and high revs (more power) as the revs increase and decrease. Variable valve timing, you could say. When you turn on the ignition it rotates back and forth (flips between low and high mode) to scrape off soot. The resting position should be over the hole because they used that hole to fixate the valve in low-revs mode (and turning off or removing the solenoid actuating it) when they restricted bikes, but I believe they stopped using that method after 1998 or something. If it does not rotate back and forth with an audible "bzzt-bzzt" when ignition turns on, your YPVS is not working and stuck in either of the modes. As for the inlet manifold I did a thorough CFD analysis and found that you cannot improve it. Leave the plastic bottle on, it smoothens out the gas flow. The carburetor should not need anything either, it is likely a Mikuni TM28SS with a 240 µm main jet, which is perfect.

@markus-w You told me to cut the wires and keep them apart lad. That didn't work, what i did was i cut the wires and connect them at the right time to somehow bypass the restriction.

@Hark_Ptooie It’s a bit of a headfux isn’t it? The read switch might not be a simple magnetic on/off by the looks of it. It might set to a default mode if it the CDI doesn’t detect a continuity in the curcuit? @Blasterguy It would be helpful to know if it only restricts the revs in top gear, or every gear? I would try joining the wires at least once to see if there’s a change at all… It might be easier to get an earlier CDI than a read switch…

@SpookDog I'll inspect the power valve from the exhaust port and try to post pictures later, just to be sure The bike feels fast and has good acceleration so there's a possibility that it's just my speedometer that's screwed up LoL

1997: [image: Screenshot from 2023-09-04 00-57-29.jpg] Hilarious thing, but it developed a plenitude of electrical problems that I was to inept to manage, so I sold it cheap. Regrets.

@SpookDog Me on my 170 No maybe not quite that low, but that's what I've come to appreciate with the Yamaha now. You look back 15 years ago when I first used the Athena kit and you'll see a completely different opinion from me. But now I have my other screaming two strokes, I am happy to have a DT which doesn't need to be revved to the moon to enjoy. But oh boy I've had some good rips home from work this year on the DT

I'm sorry for my inactivity... Thanks, everyone for helping me out! I opened the power valve and removed the rubber tube that is on top of the airbox. Now the bike gets much more air and breathes as it should, it goes like a beast. THANKS, EVERYONE!!

Yeah, go through the derestriction guide. Only when you know it’s properly deristricted can you address why you’re only getting 55-60 mph from your bike. Cause that’s not right restricted or not...

@Calum ok mate. Il speak to him about it

@Coreyp90 There's a full derestricting guide pinned to the top of this section. It covers all years and is most informative.