170cc to 184cc Big Bore Kit:

- All aluminum ceramic plated 64mm cylinder with skirt
- NEW 6/28/10 We increased the skirt height and size on the lightweight high compression 64mm piston with rings, pin, & clips to increase reliability and service life (picture is not updated yet showing piston change)
- Head gasket kit - includes the cylinder head o-ring set and an exhaust gasket.

This is our most affordable 64mm bore kit for the YX/GPX/Zongchen engines. Works great with your stock head or our new V2 Race Head.  The kit includes an all aluminum ceramic plated 64mm cylinder (with skirt) which will increase your engine displacement and power.  This cylinder is lighter than a steel sleeved aluminum cylinder, reduces friction (increasing power), improves sealing, and provides better heat transfer (runs and cools down quicker). Additionally, our head gasket kit includes a head o-ring set and exhaust gasket so you don't have to re-use your old ones or make a trip to your local dealer to get new ones and spend more money.  The new bore kit consists of high quality parts and requires no machining to the cases - bolt on and go! This kit is only for the YX/GPX/Zongchen 150cc to 160cc engines with a a KLX110 type topend.  The increase in displacement will depend on your stock engine size.  With this kit:

- A stock 150cc engine will increase to 170cc
- A stock 155cc engine will increase to 177cc
- A stock 160cc engine will increase to 184cc

There are no installation instructions, but if you can replace your piston, you can install this kit. If you don't have any experience working on your engine, we highly recommend having a professional technician install this kit. The parts are installed in the same manner as OEM parts.