Pistonkit 54mm for GK4 models.This kit can be used on all 12-volt 50cc New Model engines with the stock cilinder head.This kit is NOT recommended due to the extreme Compression Ratio that will occur when using this kit!!!

High Compression Pistonset GBO 54mm.For 6/12 volt engines with an old style 70cc head or Ultra head.This is the same piston as the 100034P but with a bigger dome for a Higher Compression ratio.