Hi all
every time I start my DT400b I get a kick back, this transmits into the ancle and its bruised and sore for a few days.
being new to these bikes and the compression, I need to ask a dumb question,
Do you move the kick starter so it is at its hardest point then kick the bike? assume this is topdead centre I dont really know or do you move the starter till it goes soft then kick the bike over? I need to learn the technique to save my ancle
Any help is appreciated

Just a comment after reading your post.  I have done 17 DT 400 and 360 refurbs and every one that kicked back had a faulty pulser coil. That was the nicest feature of the CD ignition system that it had a start pulse and a run pulse. It will probably run fine once it gets going but it will kick back hot or cold. Just my experience so far
doug

I slowly stroke the kick starter until it is just past TDC, or just starts to get soft as you mention. Then let the starter return back to the top and give it a solid, smooth boot down. Don't need to jump on it, just a solid firm stroke and it fires in 1-2 kicks. Mine does not kick back at all; you might take a look at the pulsar coil as mentioned in the post by RUN103.

PS - when I was a kid we had a 360, and it kicked back something fierce. Never did fix it, maybe it was a pulsar back then too.

wear shoes with hard soles
make sure decompression valve is cracking open and closing properly

My technique on all my 360's [only go one now] which doesn't have a decomp, is to kick it against compression from the top to get the fullest swing of the lever. Kicking through compression give a bouncy boost to get it through the next compression before the bottom of the kick stroke . 400 has a kick lever activated decomp of course. Kick back shouldn't happen & as said up top there check the flywheel key [pull the flywheel to be sure & Fully Tighten it after]. Plus pulser coil fault possibility although i'm not sure which type or year yours is. I had a 465 pulser fault once that was 'way' early. Bought the stator to get the good source coil but bolted the complete plate on as an easy fix--then the fun started trying to find why [big kick back & no chance of starting] so strobed it with someone turning the wheel in gear to prove what was happening.
So check crank key & if ok then strobe it with plug out & turning wheel in gear to check timing proximity.

Anyone ever introduce fuel (or WD40 as a starting agent) through the autolube connection to aid in a first start and for testing? I haven't checked a schematic to see if it would even be viable but figuring it mixes the fuel seems a possible access point and could avoid having to disconnect the air filter and get around the slide.

I use CRC 5-56 penetrating oil. There's a video up here somewhere of one or 3 of my relics running on that only with no carburettor just to see if there is life in whatever it was [LS3 most recent]. Works good. Straight in the inlet, spinning with electric drill--nek minit, she fires up out of control lol, but control is in the spray can. Found my vid but see i have the carb on but must have slide up a little to squirt under it. I guess WD40 is the same pretty much.

found another
Nek Minit

I remember that video. You spun the engine with the flywheel nut I think. Laughed my tail off when you smiled at the camera like a little kid who just got away with something. Seemed a bit dangerous but super ingenious.

Yeah that trick works good on small motors & lot easier the pushing it down the drive hoping it'll start. Did that on my Trojan vintage pushbike motor with nearly zero compression, plus my latest gifts of scrap metal RX125's x2.
sorry was thinking this vid shows crc startup. Initially i had the bare bones motor bolted in the bench vice sitting vertical, no carb or manifold--but i had spark "excitement" so crc down the inlet then whiz with drill & away it went. Had to have a cuppa & a lie down after that. Something about the first startup after 50 years or whatever.

I'm thinking RUN103 is spot on with his pulser coil theory because my DT360A and my DT400B have both been converted to points and condenser setup and neither of them kickback and both of them start very easily. It was the best change ever, but it is obviously no longer original. But if you've seen any of my photos on those two bikes, they are my own creations.