This
https://www.gvabrands.com/gio/dirt-bikes/gio-gx250 bike?
From the picture it's powered by a OHC machine, CRF230 (65.5*62.2) is similar if stamped as 166(5)FMM.
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What's on ur bike -Ac or dc-cdi? - Round or square connector?
Those
proven performance AC-cdi :For crf150F (early model / 63.5*49.5) /CRF230 maybe good enough...