DT125R FORUM

I use the Athena pipe with the 170 cylinder, it works quite well, and most of the power is in the midrange, even if I can get it to rev higher with modified ignition curve, the torque is in the midrange. I have seen Mick Abbey writing somewhere that the stinger ID needs to be at least 22mm (or was it 23) with the 170 kit, so that is a bit tight at least with the Athena pipe. The black paint seems to hold up quite well on the Athena-branded version.

Very nice! Welcome!

I recommend Zeeltronic too.

@hotshot-iii @aragian Gawd! I made the mistake of buying a chinese "racing" coil and that caused me so much grief. A fresh DTR rebuild and I was plagued with running issues which I couldn't get my head around. Wasn't until my brother bought his RD 350 and he took it in for a Dyno where the chap refused to run the bike due to the coil and suddenly it hit me!

I found out that the shorter rear axle collar(part numper 90387-202U8) is the same on the Wr200 and Dt. If anyone has that longer collar(part numper 90387-206X8), could you measure its length? And if anyone has a wr200 rear axle, could you measure its length? The rear axle part numbers of the Wr and Dt are almost the same WR axle part numper 3XP-25381-00 DT axle part numper 3BN-25381-00

Yes your DT will be autolube. If it wasn't... you'd have known by now. You'll need to keep an on eye on the two stroke level and refill it as it gets depleted.

@Calum Is that undeslung exhaust a custom job? I'm building a DT LC 'X' (supermoto-inspired) and want to run a underslung exhaust on it. I'm thinking a underslung DTR exhaust could fit pretty well, some minor mods will probably be needed though. I have a modified DTR Athena 170 cylinder with cylinder reed, and a Zeeltronic for that engine.

Hi Mohamed, That is a cool looking bike you have there. I am not too familiar with the newer models as it's not something we get over here and I don't know what performance upgrades are available in your region. Definitely like to see more of what you do to the bike though! Welcome to the forum.

Hello there, As far as I was aware the Yamaha DT was discontinued in 2007 instead Yamaha makes rhe WR series. That looks like a cool looking bike though, would love to know more about it. I take it you're in the Asian market, hence why this is still available. I didn't know that the bike was still being produced there. I'd almost argue the bike's styling is closer to the 80's LC model vs the earlier 70's model, with the bike using an aircooled design over the liquid cooled variant. Sorry I can't be much more help than that, still cool bike though!

Thanks for the good answer. I would like a slightly longer swingarm, so the dt200 swingarm does not meet my needs. Wr200 swingarm would be a bit longer, but requires more work...

Could be a lot of things.. but everything is probably not as it should be if it's not starting.. What I can think of: -Leaky crank seals -Damaged/leaking reed/intake -Carb issue -Ignition angle off (flywheel key?) Is the spark plug wet? Is there a good suction pulse from the carb when kicking it? With some experience you can feel it if you cover the carb with your hand on full throttle while kicking/cranking the engine. It should not blow, only suck, and the pulse should be 'strong enough'. Old fuel can make it hard to start too.

@hotshot-iii That's a very cool video and local to me too! A crated Banshee, wow what a museum piece. I had no affiliation with the Banshee prior to this build, but what a machine and what an era for motorcycling. All lost to time now and kids these days won't know the joys of machines like that.

Sadly Imgur is no longer accessible in the UK. So I am not able to see the photo. But in essence, yes the bullet connector for the loom connects to the neutral switch on the gearbox. So using a spade connector and a wire to go to the bullet connector.

@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...

Merry Christmas everyone!

@Calum @raceraidan Interesting thread. I once owned a 1998 DT125RE French import which looked identical to a DT125R the same year (pic 1). It had a larger battery and separate toolikt compartment as well as the electric start wiring. [image: 52481614948_a84fb86893_b.jpg] During this time I was fortunate enough to source a Yamaha service manual for this exact model, I still have this and here are some pictures of the wiring diagram. I believe KTM also used this engine/electrical platform for the LC2 125 which they sold a lot of in Germany (I bought 2 or 3 3MB CDI units marked LC2 125 from German breakers, and also some NIP 3MB YPVS servos which had both the Yamaha and KTM part numbers on the packaging (sadly now all sold). During my ownership I tried all these items on the bike and they all just plugged into the loom (same connectors) and worked. I'm pretty certain the (inverted) flywheel and stator were both stamped 3MB. As you can see this model also has a clutch switch which IIRC, with the clutch pulled in, allows you to start the engine in gear even with the sidestand down, but cuts the ignition when you let out the clutch to try and pull away. If you've already looked at the sidestand switch I'd locate this and give it a dose of WD40 etc. as a starting point. Also the two relays (items 12 and 13) are worth a look although I'm not sure how you'd go about testing these. It might be of some help to just get some more and plug them in and try them. Here's a link to the KTM parts fiche; search Google/eBay etc. for the KTM part numbers as well as Yamaha France and you might get lucky with a European breaker as they can be quite diligent with posting up used parts for sale including the original numbers: https://www.trevorpopemotorcycles.co.uk/index.php?main_page=ktm_fiche_finder https://ypec-sss.yamaha-motor.co.jp/ypec/ypec/b2c/html5/app/en_GB/parts-search/index.html?ver=bd30d8f2-88bf-45bf-81ba-b46167a61f3c Here are some pics of the wiring diagram, not sure if the Gilera SC125 used the same electrical platform but hope this helps: [image: 53464155671_38fb444afb_b.jpg] [image: 53463243007_9a4dea8951_b.jpg] [image: 53464293058_21dae26cab_b.jpg]

@matt0084 Yeah, I only say that as it is a known issue where the cables get mis-installed and the servo doesn't operate as intended. I find that the alignment hole in the cylinder doesn't allow the valve to sit flush in the port. I always align the valve with the exhaust off to guarantee alignment.

Hello @matt0084 and welcome to the forum. Amazing, what a choice for a bike at 17. Thanks for taking the time to say hello. Yes, you always have to start somewhere and the DTRE is a great bike to start with. That's where I started out learning about bikes/mechanics all those years ago and then the passion for bikes just spiked!

@ChuckSR86 Do you have a DTR or a DTX? [image: yamaha%20dtx%202006.jpg] or [image: yamaha%20DT%20125%20R%201991.jpg] I must admit, if it's light greenlaning, then you can get away with it on supermoto in the summer? Anything more hardcore then some knobbley's would be ideal. For simplicity, I'd be lacing a set of hubs with ally rims for knobbleys. That way you only need to swap the wheels and not the brakes.