JR50 rebuild

[bro]

I am looking at a top end job on my girls '80 JR50.
According to the frame sticker it is a model 'X'.

I cut the following lines out of a bikebandit parts list but can't quite figure out what is what. I am guessing OS stands for oversize, but it only shows certain sizes of rings for certain models??

Are there differences on piston/ring sizes between models on these little guys? Seems unlikely.

Thanks for any help you can offer.

3-1: PISTON,STD
[MODEL C] 478218-001

3-2: PISTON,SET .050
[PISTON,SET .050] 1092865-001

3-3: PISTON,SET 100
[MODEL K2] 1092866-001

4-1: RING SET PISTON
[MODEL P/R/S] 478389-001

4-2: PISTON RING OS.
[MODEL C] 478509-001

4-3: PISTON RING OS1
[MODEL T, X] 478510-001

 

[Skitspuce]

I got a piston and rings from the our local 'Zuki shop, and all I told him was "JR50"...never asked me a year. What he gave me worked just fine, and ours is an old-skool '85.