What class DT400

[jimson]

I think its 74/75 what class would a YAMAHA  dt400 run in is it the same rules as VMX this is for dirt track bike setup.jimson

[Freakshow]

same rules. if its a 400cc yhen try pre 78.

[Tim754]

 Totally Correct Freaky , Jimson DT360A is the cut off .The DT400B and so on are the post cut date models. There are no follow models allowed with the Yamaha trailies as they did physically change from the 360A to the 400B.

[mx250]

A DT400 has no class at all

[firko]

We have a DT400 farm/fork around bike and one day after a fair bit of rum decided we'd try and blow it up. We ran it on straight petrol, revved the shitter out of it and waited for the bang. Fortunately she just kept on going. Ten years later the old thing is still plodding along, a little rattly for sure but she is still going. One day we'll reward her by giving her a rebuild and transform her into a racer. She deserves it. Good bikes those old DTs.

[Freakshow]

DT anything is still fun and competitive in any year for flat track, you got to remeber you dont need swanky travel shocks and rebound dial in forks, your going round in cirlces litterally, so you can still build anything pre 80 and be competivite cause its all dual shock freindly, heck i seen fast 90 model dual shock bikes that would smoke most late model chook chasers.

Just build the bastard and race it, dont get bogged down on the classes.

[firko]

Oh Freaky! DT400s are good bikes yeah but being competitive at dirt track is another thing. For a start suspension set up is equally as important for DT as it is for MX. That "swanky" suspension is still needed. The stock suspension on a DT400 needs quite a bit of TLC to really work properly. Stiffer front springs are a start as is quicker rebound rear shocks. Then you'll find that the steering geometry will need to be improved by fitting Arces or TY triple clamps or better still frame surgery. It still won't be perfect however as the DT400 is a heavy old lump that needs to diet drastically (like me :'().The horsepower factor is way down as well and it'll need quite a bit of fiddling to even stay on the same part of the track as a good race bike. I don't know what's competitive in SA but here in NSW a DT400 in fairly standard trim isn't going to cut it. A stock Elsinore 250 let alone a 360 Bultaco Astro or a 440 Maico will whoop it all over the track and over here many of the fast Elsinores are putting out 45plus HP which would really leave the old DT behind. To be serious in Dirt Track you have to spend serious money and if you're going to spend that kind of bucks, there are better money pits available.

[Doc]

Everyone said TS400 were too heavy and too underpowered but I wouldn't listen and went ahead and built a   racer anyways. Now, in hindsight I too agree they are too blinking heavy and too underpowered to be considered a serious threat but...as a play racer it's perfect!! and like Firko's DT, you simply can't kill them. The Institute being the exception to this rule it may go okay on a flat track but I doubt I'll ever go there to know 

[Freakshow]

Meh... i just want him to do somthing with it and it would be more compeditive going round in circles than up and down on the bumpy stuff.  IM not saying its a surefire winner, but as a cheap fun bike for racing around on why not, unless you serious like you say and wanna spend some coin, but why ? he has a perfectly good bike to mess about on.  guess its up to you.  Just do somthing with it thats all.