Steve Y. - I agree with you for the most part... about not needing any mod's, and in Sparky's case, he's a HD mechanic so probably can handle a small 2 cycle without any help... BUT... in the case of a 30+ year old ringed engine, even if it's new in box, I would suggest to the average user to have it professionally "CLA" (Clean Lube & Adjusted as the saying goes) by someone like Randy Smith, not necessarily modified by anyone. My guess is that Randy would clean the engine, put in new bearings, maybe a ring if it's damaged from dry flipping, then reassemble it, and not "modify" a dern thing. (Randy, help me here!)
I can say with some authority that these old motors very possibly can have the ring and or the con rod stuck from sitting. So, what? Well, the first time you go to run it, the ring breaks and may or may not score the sleeve, or if it doesn't break but stays stuck, will egg out your sleeve, just like an improper ring gap would, and if the rod is stuck, it may run what seems "fine" for a while, maybe seem a bit down on power, as it eggs out your nice lower rod end because the upper rod end is not moving freely on the rod up inside the piston, which is also egging out the rod hole in the piston. (ask me how I know) The bearings may or may not be stuck, and will flat spot the balls in the race on you in short order if not cleaned before running also, and if the bearings are rusty, the rust breaks loose and runs through your sleeve and ring to get out the exhaust port, and if the plastic bearing seals are old dried out and cracked, the front end of your new stunter will be oil soaked in short order. Nice huh?
I guess it boils down to if you want your nice "new in box" 30 + year old engine to last 50 flights or 500 flights. Up to y'all. Ya pays your money, you takes your chances.
EricV