Yamaha DT400 Scrambler | Purpose Built Moto

[@PurposeBuiltMoto]

Make sure you check out all the details and gallery on this Yamaha DT400 Scrambler here: purposebuiltmoto.com/1978-yamaha-dt400-scrambler-2/

[@kymmillbank8889]

I bought the DT400 in 1977 as an 18 year old. Great bike.

[@Partimepeasant]

I had one when I was in the military. My favorite.

[@danielbridgewater3444]

That is one sick looking scrambler. A work of art.

[@rotaxtwin]

I don't think clean is the word, it's beyond that, especially that wiring under the seat, wow. We can all learn from that. Great mix of old school retro bike with modern touches - just as it should be.

[@PurposeBuiltMoto]

Thanks 😊 we have a lot of video tutorials and wiring blogs on our website you can check out.

[@davesears5264]

Man they were great bikes I had two back in the day used to wheelie well , they were the same as the dt250mx but with 400 lump great.

[@tonybyrne7573]

WOW WELL DONE GUYS "SUPER NICE" // TONY SOUTH AFRICA

[@bluestripes1]

nice job with the headlighht shroud

[@outfitr9703]

Wow super nice resto mod.

[@dennisyoung4631]

Awesome Buzz-BomB!

[@hughmac7423]

Cool, I have a 1974 DT400 that was modified for vintage motocross in 1988, and I raced it for a time. I have some later model parts on the motor, it is a monster to ride.

[@PurposeBuiltMoto]

We love hearing that!

[@jeffreystroman2811]

I could spot that bike immediately, my second, sorry, third motorcycle was this bike, must of had the tank off a hundred times to solder up the leaks from rust. Was a labor of love mind you

[@mattdonna9677]

I had a 1977 DT 400, bought it new for $1,000. Put an MX head on it, magnesium front air forks, a throttle that was wide open at 67 degrees, and D.I.D. rims. I miss her😢

[@redtobertshateshandles]

I owned a DT250D. Always thought a 400 would be the go. This is great.

[@Straightleg55]

Beautiful

[@deanwaring6100]

Very nice 👍🏻👍🏻❤️

[@markdelichte5401]

Very nice

[@teamgonzo9289]

Had a lot of fun on my, 1978 DT-400. It was monoshocked. A long way from the DT-1. But not really. (A 250 turned out to a 397cc/ with a piece from here, and a piece from there.....)

[@christopherlennon7246]

Absolutely stunning, lovely looking example of a DT400 Fair play to you guys, yous know how to do a thing rite 👌

[@danielryan2317]

You lads are onit, loved everyone I've seen so far

[@artiexr222]

Awesome build the ultimate combination of old and new well done to all concerned,

[@PurposeBuiltMoto]

Nailed it!

[@andrewbecker3700]

Had a '78 DT400. Was .80 over Wiseco piston with Boyessen reeds, .220 main jets, soundmaster muffler on a stock pipe with pod air filter. 16 tooth front sprocket 43 rear. The thing was certainly fun everytime I rode it. Honestly, with some modern suspension under it, I'd be going mental on one. Great engines.

[@PurposeBuiltMoto]

Yeah this bike is a real experience to ride we love it!

[@andrewbecker3700]

@@PurposeBuiltMoto Your going for the restored factory stock builds. The one I built in the early 90's was a complete mod project, with the frame being stripped of every unused bracket or hardware and repainted. Custom side covers and eliminate the oil injection system and compression release valve. I was running batches of premix that were soo wicked, with 93 octane leaded premium and Klotz Nitro Octane booster(the leaded type) mixed in liberally! The idle was soo violent the whole bike would shake like a giant bumblebee.

[@toddjacobs5660]

That is a very nice bike, looks excellent 👍

[@richa1377]

This bike came out beautiful...Around 2001 2002 my cousin and I were riding (15yrs old) and he had a 1977dt400....wow holy sh*t did that bike have power

[@PurposeBuiltMoto]

Your first time riding a big bore 2 stroke is not something you’ll soon forget

[@CHUNKYNUGGET666]

Damn that’s nice!

[@Slane583]

Very nice. This is the type of build I'd like to do with my recently acquired 76 IT400, but not to this extent. It's already missing the seat, most of the air box and the rear silencer along with some other stuff that will be too expensive to replace if I went with original NOS replacements. So I'm going to making it to my liking, though I don't care if it's road worthy I just want a fun dirt bike that's different. :)

[@Clearanceman2]

This is fantastic. I'm always on the lookout for an old DT in decent condition. I'd love to have a 250 just to put around on. Leave it street legal.

[@edsyphan3425]

I had a 74 DT 250 from new. My first bike. I don’t know if the average rider will appreciate the work you did. You did an unbelievable job on this machine. If you only did one thing, it was to get rid of those god awful drums! I just sold off a ‘13 XT 250. Nice little bike, but no comparison to the old smokers. Again, great work. I will be a sub from here on.

[@PurposeBuiltMoto]

I appreciate that Ed, thankyou. We have a few more VMX style customs in the works at the moment. You’ll see them soon

[@dikyfebriansya5825]

Gila sih ini,keren bettt....kelazzz

[@victorcolombani9081]

❤ magnifique

[@aakashganguly5433]

Hip looking Scrambler, great work!! Would love to see a scrambler built on an Interceptor 650 by Enfield, with a 21, 18 inch wheel setup.

[@bananabrooks3836]

That 'air filter' having no lid is suspect. The 'fenders' also indicate this will not see dirt again. The 'swapped out' Mikuni was fitted as stock. The presenter condradicts himself about the efficacy of the excellent Yamaha oil pump. Still it's nice to see some effort put into the Mx version of the DT400, which has some quirky design features that do not lend themselves easily to an attempt to modernise. OEM parts are also hard to scource.

[@allendabold5611]

that's very coolthat's very cool

[@j45acp69]

I love this build, super clean. Very nice professional job!

[@michaellaini6984]

Was hyped when u took the offroad

[@PurposeBuiltMoto]

Definitely wasn’t the plan, but that track along the creek looks too damn good.

[@pilothound1582]

Looks wicked dude!!!

[@dleebox2268]

Really nice 😎

[@benoshea8709]

Looks so sick Tom, such a clean build

[@PurposeBuiltMoto]

Cheers Benny, hopefully see you out on your own bike soon!

[@dleebox2268]

💯👊🏽😎

[@MichaelTucker]

I remember the first thing anyone did when buying a Yamaha was to replace the steel fenders with plastic. The stock grommets made for an easy fit. The next thing was the stock shocks and front forks which usually got a makeover. The stock handle bars were an odd shape, so they got a change out as well. Most road legal 2T bikes were fitted with an oil pump for easy fuel stops. My first job was assembling Yamaha bikes for the then South Australian distributor Pitmans.

[@tazyt3388]

Slick as batsh&t mate old school bangers are my favourite brilliant build guys congrats

[@PurposeBuiltMoto]

Cheers Tazy, hard not to love this thing

[@MotoMango]

Sick fricken build!!

[@PurposeBuiltMoto]

Thanks Mr Mango!

[@Kash_Moto]

Absolute beauty!

[@andrewbecker3700]

I'd estimate mine could hit 125mph with the gearing I had, and I'm talking about it got there fast!

[@pbaldwin18]

Dang! Hella of a build! My family has a 78 DT400 since new. Still one of the most exciting bikes to run. Hope to find a bottom end kit for it soon. Likely never been done before

[@PurposeBuiltMoto]

A fresh motor on these bikes is a pretty simple task, it will definitely be worth it.

[@Slane583]

Since your post is a year old I don't know if you've found what you need since then. But VintCo sells brand new crank bearings and crank seals for these DT400's. If you can't find anything for a DT400 look for parts for a YZ400. The DT400 and my IT400 are all based off of the YZ400. Engine parts for all three are interchangeable. :)

[@danielryan2317]

Sick 😫 🤒 😷 🤧 🤢 love ❤️ 😍

[@Speedytrip]

Wow...can't wait!

[@axlsavage]

It needs more power. Swap a IT400 top end. It will be more fun!

[@PurposeBuiltMoto]

Its already got enough mongrel in it to satisfy the rider. any more would just make it more unmanageable on road.

[@seis5241]

Okay holy fuck finally i found this im working on a dt 400 dreaming about Making something just like this im really happy thank you guys new suscriber

[@PurposeBuiltMoto]

Video drops this week, come along for the premier of the clip and I’ll be there answering questions

[@maljohn1414]

It sounds exactly the same as my then new DT360.

[@89HondaCR500R]

Wondering what all was done to convert the forks over regarding the neck bearings As the dt400 neck bearings are reusable ball bearings and most all usd forks from the 80's forward have roller bearings and im wondering what was done to adapt the triple clamp

[@PurposeBuiltMoto]

Check out the fork swap blog on our website. It has all the info you need

[@reillystsb]

Great build I would have incorporated the factory decals which may be my own Custom color.... Thanks

[@eag8999]

This is an enduro bike. Were these used in motorcross?

[@PurposeBuiltMoto]

I’m sure in the last 50 years someone, at some point, somewhere has pointed a DT at a motocross track. Maybe even 2 people, who knows

[@eag8999]

@@PurposeBuiltMoto I’m sure. Sick build, but not meant for mx. Wouldn’t want it to be, but you just said it a lot.

[@brycesimp869]

Any modifications to the engine/top end? It seems like it goes faster with lower revs than my stock 400. What gearing are you running?

[@PurposeBuiltMoto]

We’ve done a new carb and ignition system, running an 18” rear with standard gearing

[@mattimus336]

I really want to do something very similar to this with my KTM 500mx

[@PurposeBuiltMoto]

😍😍 holy shit yeah, bring us that bike!!

[@mattimus336]

@@PurposeBuiltMoto unfortunately that just isn't in the cards for me right now. Though I will definitely be using your parts catalog when the time comes. Texas is a long way off from y'all anyway, but your work is inspiring.

[@torr-michaelbennetta9785]

What triple clamp was used up front to both accommodate the KX250F fork, as well as be the correct steering tube length & bearing diameter to work with this frame?? Was it the OEM KX triple clamp?

[@mitchdefreitas795]

Love this build! Could you tell me why you didn't swap the rear as-well with a modern wheel / disc brake system? im looking to mod mine in a similar way 😁 Epic metal work btw!

[@PurposeBuiltMoto]

we just didnt feel like it needed it

[@DaveZee01]

​@@PurposeBuiltMotoDrum brakes work just fine on light dual-purpose bikes and require minimal maintenance. No maintenance done on my 2015 Honda XR150's rear drum brake to date.

[@Motosportz]

I like it but... Those fork guards look short enough to catch under the fork lip if (when) bent back. Also, fix that front brake line routing!!!!

[@jjsteez]

I'm also busy restoring a 1977 Dt400. And I noticed you put the rear brake rod below the swing arm and not above like standard. Is there a reason you've done that? Just curious, because to me that seems like it would pull the brake when the suspension is compressed. And I also feel like it's more exposed and easier to catch on bushes you go past Otherwise this is an insane build, I'm super impressed well done🙌🏼🙌🏼

[@dgratt02]

I second this

[@jeffreystroman2811]

Where it lands makes all the difference, if it maintains a parrelegram throughout the suspension travel it won't affect the braking. If it lands closer than a parrelegram it has the nasty habit of hitting the brakes when hitting a bump, not a good place to be

[@kiwiriderandrewwright.theo7820]

Nice! I'm on the hunt for one too so i can peel the road bike guys through the twisty bits.They got massive torque & you can gear them to use it on the road as they not a great dirtbike anymore. What speed did you get out of it as it looks to have moon gearing too? Ta guys

[@lukasrgl]

Such i cool build i think i have to make something similar myself, with the dt400... How did the KXF Frontend fit? Did you have to Fabricate something or does it just work

[@PurposeBuiltMoto]

Everything has to be customised Check out our website blog for details

[@miriataaki7634]

Send the bike to Mangaia Cook Is

[@PurposeBuiltMoto]

Send me $20

[@1969cmp]

Hmm...so if I can source a Honda CR500, you be the blokes that could build an HRC RC500 'Thorpe-Bailey' replica.

[@PurposeBuiltMoto]

Yeah definitely, sounds epic!

[@cadenmartin2849]

what triple clamp ?

[@kokigephart111]

Not really impressed. Leg burner, no heat shields, no battery reserve, head light blocked by fender, chopped rear fender loads mud on shock and airbox, woods riding with buddies you need better brake light, seat way to thin , low capacity gas tank that you have to lean over the bike to move gas over to petcock side.

[@thejald3049]

Can you please share ur contact? What didn’t cost to built this ? Thanks

[@PurposeBuiltMoto]

You can contact us through the website linked in the video notes

[@user-rw4fn3dj6e]

Another great vintage bike ruined for the sake of being cool. Sorry I'll keep my '80 Husky from being turned into a so called "scrambler" or "Cafe racer" for some hipster that has the money. Oh well to each his own.

[@PurposeBuiltMoto]

If you want to get really mad, you should go watch all of our other videos. Then buy yourself our wrecking crew t-shirt purposebuiltmoto.com/product/wrecking-crew-tee-3/

[@user-rw4fn3dj6e]

@@PurposeBuiltMoto I do appreciate your work! A very fine job. Im just a crotchety old man. Btw i do have a 77 DT250 that i bought new, my first vehicle.

[@redtobertshateshandles]

There's nothing really special about these late DT's. A few mods doesn't hurt. They're basically a great engine with ordinary everything else.

[@miriataaki7634]

Send the bike to Mangaia Cook Is