Motorcycle Repair: Honda CT-90 1969 K1B, honda ct, honda parts

Question
I have a bike which was running fine this summer.  I let the oil run down more than I should have and did some damage.  When I pulled it apart I noticed the upper ring was missing and the piston was badly burnt.  The parts are expensive and hard to get.  I want to know if there is an engine from a later model or other bike that is compatible and cheaper in parts.

Answer
Any of the 90 CC engines will fit that bike.  The 110 cc engine were almost identical if you want to swap the whole engine but the rings and piston won't fit your cylinder.  I'd look around some or check the internet for aftermarket parts.  The Honda parts are expensive but aftermarket stuff should be reasonable and available.  They made a lot of those bikes.

Regards
Rich