WORKS WITH 120CC LIFAN AND ZONGSHEN ENGINES THAT HAVE 55.5 STOCK STROKES AND 52.4MM BORE'S I DO THINK IT WILL WORK WITH 125CC LIFAN AND ZONGSHEN WITH 54 X 54 BORE AND STROKE (MEASURE THE BOTTOM OF CYLINDER) IF IT IS 58.4 OR BIGGER IT SHOULD WORK FINE. THIS HAS A 14MM PISTON PIN THIS KIT WILL WORK ON LIFAN SDG OR ZONGSHEN ENGINES THAT HAVE A STROKE OF 55.5MM OR 57MM.. THE FOLLOWING LIST WILL BE ALL THE DIFFERENT BIKES AND TRIKES THIS WILL WORK ON LIFAN & ZONGSHEN ENGINES WITH STOCK 52.4MM BORE AND 55.5MM STROKE LIFAN & ZONGSHEN ENGINES WITH STOCK 52.4MM BORE AND 57MM STROKE SDG THUMPSTAR GPX PITSTER PRO UPC XTREME ICON 'S ..WITH THE ABOVE LISTED ENGINES S1111