Yamaha DT125R '01 - Running Project



  • @andrewj1680 Oh man, that sure looks damn sweet, and such a shame to do all that work and then get all that lovely shiny metal blacked out. But hey-hoo I get why and it was your choice.



  • @CYBER-NINJA I preferred the polished look but I'd of spent more time polishing it than riding it every time I took it out, Can you imagine trying to avoid every puddle you came across lol that wasn't for me if it's there I'm gonna ride it



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    (6mm Stainless Steel - Brass 13-14mm spacers)

    I made DXF files for Waterjet cutting - for a Stainless Calliper adapter and spacers for a SM conversion using the 'YZF125' Brembo calliper.

    If there are a few members here looking to do SM conversions, I could get a few kits together with bolts,

    Just a limited run as I have the time for the moment.



  • 32 degrees, sticky rubber, cotswold country lanes, 2strokes and considerable beer intake on par with University life.

    I ride this thing 22 miles a day as a daily to go work, built this thing to be used and I just 'turn it up' a little on the Laptop for a blitz on the weekend somewhere.

    Drawing this project to a close, and enjoying the result, or atleast this iteration of it so far...

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    I had some clearance issues with the Powervalve under expansion. I removed material in increments by machine sanding.

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    Custom bracket for the FMF Powercore1 can. Fits on a DTR well.

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    Built the headlight brackets,

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    WR400 Face swap.

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    There is no room left on this bike. Made a mount for the Ignitech Ignition, secure, doesn't suffer from heat exposure and most importantly it's accessible.

    As for cooling, air flow is fine still.

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    Modified AS3 Silicone WR200 radiator hose's to suit this mongrel application.

    This leads me to something interesting I found,

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    I needed a new WR200 coolant pipe, turns out later 4BF4 1995' WR200s use a larger 18mm bore coolant pipe.

    I got one brand new old stock from Japan. I've rust protected it, primer and a Gold top coat for a little bling.

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    Then of course a 4BF4 Waterpump cover is required.

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    4BF4' Pictured above vs 125R/200R

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    I never knew Yamaha updated the cooling for the WR200, so I had help getting a used one.

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    IT ONLY JUST FITS... Tight bruuuh. I made a brace for the coolant down pipe as it's just a braised joint and I managed to split my last one like a clot.

    Originally this mounts onto the WR200 Cylinder, so ideally this has to be done to the 125R barrel.

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    Cooling is now more than adequate,
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    WR200 Inlet, TM32 fitted. This inlet gives you more angle to use larger carburettor bodies.

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    WR200 vs DT125R. Inlet tract a little longer, Mounting points have to be modified and crankcase stuffers removed.

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    New YZ braided brake lines and removable exhaust joint to get the FMF onto the DEP.

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    (An oldschool mechanical display setup. Dorky but I love this older stuff.

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    The fun bits. Built to be ridden alot!

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    Using a base map close to a TZR125 4DL SP, It runs particularly well under 6K.

    This DT now shifts.. I use a 4DL servo setting which utilises the PV opening later than the DT or TDR 3SH.

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    It's far from perfect, but a safe base tune to run on as this is my daily as the weather is so good.

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    It's run in properly now, and it is glorious. It sounds fantastic over 10,000rpm.

    Powerband is up at 9,500rpm and it pulls hard to 13,000.

    DTR Gear ratios are perfect for this TZR head and it's acceleration characteristic is spot on, 0-62 less than 6 seconds.

    More to come, more bits from Japan to arrive and then finally a Dyno session with a TM34ss fitted.

    Stay safe!



  • @Darty my power comes in at around 9 but only pulls for a bit is this normal just because you have a fancy set up?



  • @Darty btw that bike is legendary well fucking done man



  • @declan Cheers boss, yeah I guess it hasn't risen much, it's not running right at top end RPM's. Possibly the Reeds failing.

    It's amazing how much more torquey it is than before, it's not a bad commuter bike still 😂



  • @Darty Oh my, yes bud this is fantastic!!!!! 😃


  • Global Moderator

    Very interested to see the dyno results!



  • Yeah me 2 🙂



  • hey, are the calipers you designed for the dtx front brake? or is it for dtr front brake? because if it is for dtx front brake i would be interested



  • Thats a cool dtr!