I bought a 167FMM CG250 (233cc) Chinese copy engine. I’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 don’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 isn’t big enough to accept the larger cylinder liner, so today I set about boring the crankcases to accept the bigger liner.
Fixed small oil leak from the rocker cover, tightened steering head bearings, adjusted front brake, dialled in the idle mixture on the carb. All sorted.
I had the day off work today. Got my CeeGee through compliance and then decided to further investigate swapping the Chinese CG250 internals into Honda CG125 cases. Got quite a long way in when I discovered the main bearings are different sizes. Gave up and put it back together. I’m so chuffed I bought a small Makita impact wrench. Made the process so much faster and easier, although I did have to get my air one out a couple of times on really tight things. I didn’t know but square number plates are now a thing 👍
All ready for compliance and new number plate next week.
And it lives I was beginning to despair. Turns out the wires from the stator were in really bad shape where they went through the grommet on the engine case. I cut them, soldered them back together and shrink wrapped them.
Got the crappy Chinese carb sorted, was full of swarf and had a pinched bowl gasket. Strip, ultrasonic cleaner bath and reassembled and it’s running good now 🙂