169fml engine identification

franque · 04-10-2022, 01:23 PM

The first digit indicates the number of cylinders, the second two refer to the nominal bore diameter (though there's a chance with older engines that this is mislabeled but is also generally rounded, as I presume it to be in this case).

There isn't a direct correlation to bore diameter and displacement, the engines are classified by their class, rounding up, and there are even some examples of different engine architecture being labled with the same letters because of the simplicity of the engine labeling system, for example Zongshen copied the TW200 engine (using a conventional transmission, I think they were used in the GY-2 motorcycles IIRC) that was the 167FML, and there also were CB/CG models that were labeled 167FML, despite the fact that the crankshafts, cylinders, and cylinder heads would be different. There are also 166FMMs which are "250" engines that are generally based on CRF230 engine dimensions.

The F (which can be other letters, too) indicates that it is regular air cooling, the first M is for motorcycle, and the last letter indicates the displacement class. For example, a 167FMM is a horizontal single cylinder "250" class engine, likely around 223cc, while a 1P54FMJ could be a 140 or 150cc vertical motor. A 1P39QMB is a 50cc class scooter motor, likely in the GY6 family. A 125cc vertical CG/CB motor would most likely be a 156FMI.

Refer to this post to decode motor identifiers in more detail:
https://www.chinariders.net/showpost...51&postcount=6

04-10-2022, 01:23 PM	#5
franque Join Date: Nov 2017 Location: Marseille, France -> Conakry, Guinea Posts: 1,481	The first digit indicates the number of cylinders, the second two refer to the nominal bore diameter (though there's a chance with older engines that this is mislabeled but is also generally rounded, as I presume it to be in this case). There isn't a direct correlation to bore diameter and displacement, the engines are classified by their class, rounding up, and there are even some examples of different engine architecture being labled with the same letters because of the simplicity of the engine labeling system, for example Zongshen copied the TW200 engine (using a conventional transmission, I think they were used in the GY-2 motorcycles IIRC) that was the 167FML, and there also were CB/CG models that were labeled 167FML, despite the fact that the crankshafts, cylinders, and cylinder heads would be different. There are also 166FMMs which are "250" engines that are generally based on CRF230 engine dimensions. The F (which can be other letters, too) indicates that it is regular air cooling, the first M is for motorcycle, and the last letter indicates the displacement class. For example, a 167FMM is a horizontal single cylinder "250" class engine, likely around 223cc, while a 1P54FMJ could be a 140 or 150cc vertical motor. A 1P39QMB is a 50cc class scooter motor, likely in the GY6 family. A 125cc vertical CG/CB motor would most likely be a 156FMI. Refer to this post to decode motor identifiers in more detail: https://www.chinariders.net/showpost...51&postcount=6
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