do you have a manual for it , if not it comes in handy at times.
First is to get the donk on top dead centre , remove the mag cover and line the fly wheel mark TDC mark with the little notch on the case, it is at the top of the case.
I remove the tappet covers and make sure both rockers are free, because you may line the TDC mark up and its not at TDC so you have to do a full 360 spin again if that makes sense
Then you have to rotate the points plate so the points are just starting to open when you turn the flywheel past TDC .
if you have a buzz box ::)I think that's what they call it , new hook this up to the points and that will tell you when the points have just opened.
The points gap on the manual are 0.35
once you get it running you can use a timing light to check the flywheel marks line up with the F mark .
you will have to get the idle right 1100 rpm other wise the timing light marks can change when you rev it higher than 1100rpm
hope this makes sense
but the best bet is to get hold of a manual they are all ways on ebay etc.