300mm dtx rotor and wr 426 twin piston nissin caliper and master cylinder works great on my DT. Had to make a bracket of course.

Clean your carb out so you've got a good base point to start from. Your idle screw should be between 1 and a half turns out and about 3 turns out when the engines hot. If it's running better at under 1 and a half turns out then you want to fit a richer pilot jet, higher than 3 turns stick a leaner in. If this is set right the bike should always require choke from cold start, which is correct procedure.

@Darty ah right cheers, I've had no issues so far on the standard float height the carb came with, what symptoms should I be looking for? Just a bog when holding bike wot for a while? Had bike flat out for a good minute or so in 6th and never seen any issues?

Finally getting somewhere with this carburetor, sorry for the wait, had a little incident with buying a car I definitely shouldn't of bought haha.
Was having severe spluttering with the DT all the way to main jet, the bike would literally barely run under load unless you were flat out. Narrowed this down to the needle and invested in a polini needle kit. Currently running a 140 main and 42 pilot, along with the standard N68E needle. The bike actually fouled it's plug after trying to startup again after a 5 mile ride, it was running allot worse in the 15 degrees weather we had compared to when I last played with it in around 5 degrees weather. I tried the leaner JJK needle and found it was bogging on big throttle inputs, so raised it a notch to find the bike had transformed. I just went a short 10 mile ride and the bike is a totally new beast, miles better than standard carb, loads of torque from idle. The only issue I'm finding now is a splutter at low throttle say 1/8th under, so I'm guessing the pilot is rich. However upon checking the new plug I fitted the bikes running abit lean, so tonight I fitted a JJN needle, which from what I can gather will give a leaner low end with richer mid and top, I've left it in the mid position for now. Once this weather clears up Abit and I'm back off work I'll give the bike another shot and post an update, but I'm finally glad to be getting somewhere with this bike, as it was proving a minefield a while ago.

This also is why I've been in active on here for like a month, bought myself an old E36 325i and spent 90% of my time underneath it or adding parts, I thought bikes were expensive to mod, but the beamer certainly takes the ticket haha

@Nottsbiker the yokes use a different bearing type on the top, and bottoms different taper too. Standard DT 125 uses ball bearings on the top compared to tapered rollers, also 400 stem is longer, takes some spacer work and a bearing cup but the swaps doable if you have a lathe.

@Nottsbiker are you referring to the front wheel or fork assembly mate?

Don't get fooled by the fancy transoils etc for bikes, a quality semi/full synth 5-40 or 10-40 will be fine, I tried all the oils like motul transoil in my DT when it had a clutch slip problem, in the end some left over 5-30 full synth Castrol made it twice as good feeling and got rid of the slip. I usually just use what's left over in the drum from my car oil changes, however I've just bought a old 6cyl 3 series so that takes magnatec oil, which I heard can cause issues in motorbike gearboxes so I might have to invest in oil for the DT next time