Jiangdong manufacture both the TY and JD engines. Jiangdong changed the engine design during 2009 by increasing the deck height. The updated engines have an engine number preceding with a "B". Many parts are interchangeable however specific "B" engine parts are not interchangeable with earlier engines and vise versa. It is important you check the serial number located on the side of the block. If the serial number is not visible then you will need to measure the pin height of your Piston and the overall height of your Liner. It would pay to check these regardless of your serial number.

Pin height is the centre of the piston pin to the crown of the piston. JD and TY have a 35mm pin so 17.5mm plus top of pin to crown.
Overall height is the height including the seal lip. Measuring internally will give the overall height.

A series Pistons (pre 2009) have a pin height of 60mm
B series Pistons (after 2009) have a pin height of 58.5mm
A series Liners (pre 2009) have an overall height of 184mm
B series Liners (after 2009) have an overall height of 189mm