hi to all,i recently got a bo1 21 second hand it had about 2 gallons on it,it came with an xray roller which is what i was really after,long story short i was havin a look inside the engine as they are a new type to me,while takin off the backplate i must have twisted it and broke a piece off the bottom of the piston,it seems the replaement part comes as a piston ,liner conrod set and is pretty expensive whaen all i need is the piston,i normally run the go gx11 ,does anyone know where or if i can just get a piston to get the engine runnin and try it out rather than spendin the big money on it without ever havin it runnin and not knowing what it is like ,thanks in advance ,jason