Honda C90 '89 piston & barrel change

After a week or so being used as a daily ride to work, it was obvious that there must be some wear somewhere as the exhaust had more than a hint of two-stroke & too much oil was being used... We happened to have another barrel & piston which looked to be pretty good so we decided to swap them over & see if that cured the problem....

An hour or so later & it was running again... minus the smoke this time so hopefully its cured that problem?