Hello! On my '74 Yamaha DT250, I don't see anything in the manual on how to preload it and install the kick starter spring assembly. Is there a video or are there clear instruction somewhere? I have searched the internet to no avail. Thank you!

Kick shaft 10 will have a dot & stop 16 will also have a dot that needs to be aligned.
That has a relevance to spring preload.
But i'm guessing the spring in the tin cover is worrying. you.
I'm thinking back 50 years but it sits in the tin cover with the spring end preloaded behind a tab which holds it in tension for assembling purposes.
I'm guessing a bit now but when your cases are bolted up the shaft engages the spring then you turn it from there until the shaft stop 16 finds its place 'in the case' that it returns to after each kick.
So it never returns to the spring tab 'after that' but revolves about half a turn during kicking & comes back short of the tab.
I'd think if the preload tab has broken off it wouldn't be too detrimental & means you'd need to engage the shaft slot into it from further back & bring it around until your shaft stop finds its case stop.
I looked for a video without any luck sorry.
If my woffling above is confusing--i confuse myself at times lol.
Hope i've got the right model in mind but i can remember 1974 better than last week sometimes.
This will kick the post along & someone might explain it a lot simpler or easier.
Welcome from NZ by the way.

images.cmsnl.com/img/partslists/yamaha-d...gyau1065b-6_b9d9.gif

Thank you! Yes that's the one. It was still assembled, sort of, when I split the cases. I tried to upload a picture but no luck. The shaft, spring and spring cover were all together, under a lot of tension ready to explode and take my head off lol. I took lots of photos and tried to carefully take it apart, but it had its own plan. I appreciate you taking the time to explain. I thought EVERYTHING was on YouTube, but I guess I was wrong haha. 

All good. Yep i searched & searched for a video trying all alternatives of that motor like TY250 DT250A MX250A DT360A of 1974 which was when that motor design started but all turned up missing haha. Got close but none of the vids went deep into 'that' detail. Gotta be something out there somewhere. Cheers.

I wasn't aware there were alignment marks on the kick axel (shaft) and the ratchet wheel. Good to know that RT325 as the service manual is mute about that point. When my DT360s were reassembly I recall indexing the ratchet wheel so that there was a minimum amount of preload so as not to over stress the return spring. I'm not sure where the dots ended up. Here's a couple of pics taken on disassembly that show the angle of the notch in the shaft in the returned position. I'm not certain about the alignment marks but the kick starter worked fine.
(Hope images links work)

imgur.com/gallery/uBNttjq

imgur.com/gallery/BhYFY2M

I had to look back to see what i said haha. Regarding marks i was guessing there has to be some reference marks or the spring preload could end up less, or more, than desirable. Cheers. ps i'll go looking for some info on that.

I can't find any reference talked about regarding alignment dots so i don't know., i still say the has to be & won't be very visible.
But just thinking if you've not taken the stop off the shaft then it should still be good as is.
Just need to locate the spring with the shaft slot & turn then push to get it in place on the case stop once turned far enough.

For some reason my first post #2 post was still in the message box from a week ago although it had been posted.
I've had that happen before, Never mind i just cleared it & started again.