Monthly Archives: September 2020

CG250 engine project begins in earnest

I bought a 167FMM CG250 (233cc) Chinese copy engine. Iโ€™d like to use it in my recently completed silver CG125 but as the old CG125 is 6v with points ignition and the CG250 is 12v with electronic ignition I donโ€™t much fancy changing the wiring harness and all the light bulbs. So I have been investigating swapping the crankshaft and cylinder, piston etc to some spare CG125 crankcases I have. The first issue is the crankcase cylinder opening size isnโ€™t big enough to accept the larger cylinder liner, so today I set about boring the crankcases to accept the bigger liner.