Hi All, 
I am based in Kent in the UK and have recently bought an imported US 1974 DT125A to restore for my daughter (at least that was the excuse.. 
Most parts I am easily able to source but I have an issue with the ignition. The bike is fitted with the starter / generator system and there is a governor assembly which sits on the outside of this with the cam for the points,(basically the auto advance) the one I have is shot having spent too long sat in damp conditions and is unserviceable and these seem to be rare as hen teeth, certainly this side of  the pond. They don't seem available new or NOS in the US either to me, but I may be simply looking in the wrong place, of course importing even second hand parts from the US has recently become eyewateringly expensive, but needs must etc.
So I have a two part question, firstly would anyone here know of where I could get one of these, or have one available to sell?
And secondly I thought maybe a solution is to replace this with an electronic system and do away with the points system too, however again these don't seem available thin the UK so advice, pointing in the right direction etc would be greatly appreciated as if anyone has carried out this conversion it would be interesting to hear how, what the results were, and where I might source similar.
Thanks in advance for any help and advice, much appreciated.
Nigel

If you can lock advance (governor) open and/or get timing set correctly with fixed advance you'll be fine. 

Advance is only used for ease of starting... once running it's at full advance.  Might need to kick start when dead cold with advance locked open.

Powerdynamo/VAPE makes a 12v magneto conversion kit.  You will lose the electric start.



 

Hi, Thanks for the response, all very interesting. The electronic ignition option looks good, although pricey, and at the cost of the electric start, but that's not really an issue on such a small engine, most of my machines are large four strokes so a little more difficult (but even the old Z1000 kicks easily enough).
I think initially I'll try with the option of fixing the advance, I always worry about over advance with two strokes, I had a KH 250 back in the day which used to eat pistons for breakfast if it wasn't set up perfectly, taking time with a dial gauge and strobe should sort it.
Thanks again
Nigel
 

Without knowing exactly how bad your rotor is , it might be worth immersing
in Evaporust for a day or two . With the rust removed , it may be salvageable .

On that model the timing is set at full advance.  So if the mechanism is frozen and you set timing to spec it will be okay. 

Like I said, the governor is set so that timing is retarded with engine off and then timing is fully advanced when engine starts and idles or maybe a couple hundred rpm above idle.  It's not like a car where full advance happens at high rpm.

1.8mm btdc & she'll be good.

I had the same ignition in my AT1 (they are all the same in the 12 volts 125 models). I went with the powerdynamo (now V.A.P.E.) and have had great results. It is super easy to start, and mine has a 175 cylinder on it (another bolt on power improvement!)

Here is a video of starting it by hand:

Hi Again,

Thanks for all the useful help. I tend to agree it does depend on whether I can clean the rust off the existing governor and get it working again, I'll give that a try first, it will mean sourcing some replacement springs but a bit of careful measurement of the old ones before they dissolve in any rust cleaner should see that possible. If not I'll try the fixed ignition setting first. 
Thanks for the info and video on the Powerdynamo, it looks like a really good aftermarket solution, its a shame the electric start is lost but it shows that (as you would hope) that starting is really easy when correctly set up on the kick.
I like the idea of the 175 cylinder, although with this being intended for my daughter (honest) sticking to 125 would certainly make it legal should she wish to get a license when she is 17. I do have a barrel and piston from, I believe, a Gilera? which used the same engine bought from yamaha on a similar period enduro of their own, it has the advantage of effectively being unrestricted with much improved porting on both the barrel and piston, so hopefully this will have a positive effect, although I suspect a little tweaking of the carburation my be required.
Thanks again for all the help, when its a bit more than a box of bits I'll post a photo. 
Nigel