Hello,
I got around to stripping down my new Toro 25cc powerhead that I got off Ebay. It looks a lot like Echo/Koritz engines. Trimming the flange will be a pice of cake, since it is heavily vented. Very nice two ring engine. The timing is retarded like many Weedeater fleatherlite. Exhust 65 degrees,Tranfers 51degrees,Intake 60 degrees. It looks like the ignition timing is retarded also. I am attaching some pictures of the raw engine. Don't be afraid to jump in with you two cents.

Thanks, Dave