ya, i would just re-build yours. hard to say what condition the other engine is in.... you might just need to hone your cylinder and a set of standard rings ? i would also re-lapp in the valves and such.. good luck and let us know how you make out..
our original 85 we bought new, 2 - 86 police specials
250r dust runner
04 Yamaha kodiaK 450 snowbuster ! Brute Force 750 dust collector .
Bunch of es stuff I been buying for next builds....
Gone but lives on in my aching body the mighty 350x collection . A Beat 85 es im gonna rebuild