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General Discussion

A place to talk about whatever you want
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  • Please Introduce Yourself Here Before Posting!
    179 2k
    179 Topics
    2k Posts
    CalumC
    Here are the differences in the 3BN Cylinder head [image: 1483566896896-dt125rheads-diffrences.jpg] It'll be marked on the cylinder head. [image: 1663628447669-874e98a1-e604-4e06-9310-d20f77cae655-image.png] The 3BN head is interoparable with the 3MB head, but has a combustion ring which is said to adversely affect performance. Here is a video of the difference between a 4FU cylinder and a Belgarda 3MB00P cylinder. https://www.youtube.com/watch?v=P8okvTxe-Bs Here is a 3MB cylinder. [image: cylinder-1_medium3MB1131100-02_4baa.jpg] [image: 1663628477295-8e899a28-4514-4881-89ec-bfcc824ade10-image.png] You'll see the crankcases are stamped 3BN [image: 1663628512647-b054f520-0af7-4920-948f-cc532b8bbd25-image.png] For the most part you don't need to worry about it, it'll be rare that you'll find a DTR with a 3BN crank/cylinder and most of them will be 3MB cylinders. But it's just worth bearing in mind. There are variations in CDIs and Exhausts which affect the performance, but these are less important as there are aftermarket support that recitfies any loss in performance

  • This section is for members to talk about anything non-dt related. Please keep the theme and language clean to permit viewing in work.
    193 2k
    193 Topics
    2k Posts
    CalumC
    Normally, they just add a throttle stop to restrict the bike, so you can only open it 3/4s of the way. This is what a lot of the test centers do as it's easy then to unlock the bike to full power afterwards.

  • Post your jokes & funny things you find on the web in here.
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    118 Posts
    HOTSHOT IIIH
    @Stevie-Wonder Thanks bud Greta (for that is her name as she's noisy, irritating, aimed squarely at the youth market and responsible for thousands of them bunking off school all over the world) cost me half as much as my '93 due to the mileage and had a thick layer of grime all over due to years of grinding commuting. I gave her a scrub with Jizer (several times) and this is what was underneath Here are the part #s for the toolbox and lid, bit pricey IMO and you'd have to get the lugs welded on to a non-e start frame. Be a nice touch if you were getting it powdercoated sometime though https://www.cmsnl.com/products/boxtool_55v2817301/ https://www.cmsnl.com/products/lid_55v2818500/

  • Blog posts from individual members
    15 138
    15 Topics
    138 Posts
    NINJAN
    @Minia Looks nice and beefy and she sounds cool with a deep roar!!! :grinning_face_with_smiling_eyes: :face_with_stuck-out_tongue_winking_eye: :thumbs_up_light_skin_tone:

  • Content Not Suitable for Work!
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  • facundo duarteF

    Question about remachining the 3BN head while maintaining the original CDI.

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    facundo duarteF
    Regarding the CDI I have, I read the same thing, so it's fine. I was looking for Ignitech, which is a little cheaper, but it turns out that in my country imports up to $200 are tax-exempt; you only pay for shipping and the product itself. If it costs more than $200, you have to pay an additional 60% in taxes. Regarding the CDI head and curve, I was asking about possible detonation or some other symptom that might not be very positive or beneficial. I was looking at the RSA 125 head design; I didn't expect it to work the same, but at least it seems like a design I could consider reliable or better than the current one. Everything is quite complicated here in Uruguay: resources, possibilities, etc. Perhaps with a test bench or sensors it would be easier, combined with the knowledge acquired over the years. There's a visa I could apply for; it's somewhat expensive, but it allows me to go to the UK to work and travel for two years. Maybe I could try my luck there. There's a lot of desire, but the problem is the resources available here. Thanks @Calum
  • F

    Will a 90/90-21 (Vee Rubber VRM 163F) fit DTR 125 front wheel?

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    MadGyverM
    A tyre/rim chart I have says up to 80/90-21 is ok,90/90-21 is what I will put when I change tyres. Don't remember where but someone fitted that size to 1.60-21 rim and had no problem.
  • G

    WR200 front end?

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    HOTSHOT IIIH
    @GiannisT No worries The XT springs/15W oil mod stiffens up the front end quite a bit, to make my YSS shock match the forks I had to up the preload 16mm over the supplied setting and run the rebound on position 29 out of 30. If I'm honest it made the suspension a bit too stiff for off-road (I weigh 145lbs), if I'd had more time I would have experimented with cutting 10mm at a time off the DTR spring spacers to get it just right. I had Michelin Trackers (road legal MX tyres) fitted all the time I ran this setup so can't comment on street use but it's a pretty easy mod to try and it sounds like you're looking for a stiffer front end, XT springs come up for sale quite a lot because a lot of owners upgrade them (too soft for the 160kg+ XT = a good match for the DTR). Would be interested to hear if it's good for Supermoto, plus if you still want to go the USD route it won't have cost you much to try it!
  • F

    3mb expansion chamber, cone restrictor removal and re-jetting?..

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    CalumC
    @HOTSHOT-III [image: guttin11.jpg] https://dt125r.co.uk/topic/20/yamaha-dt125re-x-stock-exhaust-pipe
  • F

    Original on-bike toolbox, rubber cover/lid?.. (1992 DT125R, ex-France)

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    F
    @HOTSHOT-III Cheers buddy yes that's the thing - the box is in good nick, I just ripped the lock tab off. I could try and make something up, but it'd be a shame as the bike's currently all original/unrestored. Thanks again! Shaun.
  • tony1980T

    Lookin for exterior bolt kit ie seingin arm and engine mount

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    Hark_PtooieH
    Well, nuts and bolts are standard across industry, so you don't need some special kit. I go to my local hardware store where they have open packs of all sorts and sizes. You put them in a bag and weigh the bag and pay per kilo. Most screws I have swapped so far have been M6x12 or M6x20 with some odd M5 and M8 here and there. I usually get flanged screws and skip the washers. I do so love screws. Then again, I am a mechanical engineer so the fetishism comes with the profession. If you want to talk screws joints for a couple of hours, I'm your guy.
  • primal carnageP

    Kickstart

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  • sheamac29S

    How far has one went in one trip on dtr

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    CalumC
    87 miles...Yeah it'll do that no problem. DTRs are a work horse. 15 years and mine has never let me down.
  • C

    Searching for my old bike :)

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    markus.wM
    @SpookDog it's not a bad thing in my opinion as the 88 black with red is my favourite colour. I do like the endurance blue but the black and red just cuts it for me.
  • primal carnageP

    Got Big One Exhaust need adapter to go on DEp system

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    S
    @Scootjockey The Imgur app can be used just on your iPhone, upload to an Imgur site thread, then copy the link of the individual pic and put it into the ![alt text](COPY LINK HERE) option 2nd from the right in the toolbar above that is visible when posting to a thread…
  • primal carnageP

    No break lights

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    S
    @primal-carnage If it comes on ‘a bit’ it may be a bad earth at the tail light. Is it the same with back and front brake levers? Also have you changed to LED lights anywhere? The brake light should work off of the battery without the engine running…
  • giggscorkG

    Every Colour Scheme the DTR was released in

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    giggscorkG
    @HOTSHOT-III yes that is my video. I should also note, according to this my bike is actually a 1990 (the black and green one), although they might not be the original panels. I think its a 3RN2 model, the one they sold in the UK with the servo removed. @Calum and of course Japan kept the cooler ones to themselves haha
  • primal carnageP

    Gear shift for DT 125 R

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    O
    When I bought my 2002 dt125r it had a few apico bits on it and one of them was a gear change lever I was told that all the bits were from a yz125
  • primal carnageP

    Looking for a link for some blue break and clutch leavers that would fit my DTR

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  • O

    Zeeltronic

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    CalumC
    @old-boy-racer Hi there, Zeeltronic is just about the best bang for buck you can get in my opinion. Of course this depends on what model/year/location DTR you've got. It's all diminishing returns though, once you've got a decent exhaust and the zeel, everything else is just marginal gains. Earlier this year I fitted the VForce4 Reed block to my Yamaha. The Athena 170 kit is not a bad upgrade too if you're after a bit more midrange poke.
  • S

    Inlet carb manifold

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    CalumC
    @Scootjockey You're laughing then. It should be the 1993 TZR 4DL Belgarda. [image: $_yamaha_tzr_125_rr_belgarda_$1450486422_by_Black91pl.jpg?1450486422]
  • S

    New Crank

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    HOTSHOT IIIH
    @Scootjockey Thanks bud That adaptor is the correct size for the DTR main bearings and crankcases but potentially you could have one made for any engine. Mine was done by a local machine shop. Even when you watch the Rocky Mountain ATVMC how-to vid where the crank puller is branded "Tusk" for the US market they still transmit a side load through the bearing and lots of people have commented on it https://www.youtube.com/watch?v=p0LK30KVWJg&t=404s
  • H

    Q plate Dt125 worth restoring?

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    S
    @H22dan Hi Dan a Q plate bike will never make as much money if your doing it up, least not one on a standard reg plate due to the stigma of possibly being stolen and recovered. Years ago a mate of mine bought a Suzuki X7 from the insurance company/ police sales it was stolen and recovered and all the numbers had been ground off. The feds identified the bike allegedly by x raying the frame. And the insurance company paid out on it. He new all the old numbers and owner etc but it couldn’t be put back on the road with those numbers or the reg plate. So he then stamped his door number and post code on the casings and frame and registered it with DVLA once it was MOTd. Showing my age now but back in the early 80’s a Q plate was rather popular what with all the 250-350lc’s making it on the tracks for production racing and then being put back on the road. With that in mind they are a lot of trikes out there on Q plates that were home built with the back end of a VW Beetle. All legit just the front end will have numbers from a chopped up bike and not match.
  • S

    TDR 125 extra power

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    CalumC
    @Scootjockey I ran vapor trail digital clocks, but not because of the Zeel, but because I swapped out the forks and wheels for USDs and Aprilia RS 125 wheels respectively.
  • T

    Engine identification required 125vs?

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