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😢
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.
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
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.....)
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
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.
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.
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.
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. :)
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 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.
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.
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
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. :)
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
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?
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
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🙌🏼🙌🏼
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
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!
@@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.
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 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.
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.
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.
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/
@@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.
