Are you talking about generic scrap, or bike scrapyards?
There might be some light at the end of the tunnel, signed up with a 3 wheeler forum, and a little searching, found that the cam from an xr200 dirt bike will fit in my atc
and better yet, they are relatively cheap, and even better, looks like they make more power than stock
I found one:
http://www.ebay.com/itm/HONDA-XL-200...96b20c&vxp=mtr
Still looking for the pulse generator parts......