

$135 for the complete kit.
This 72cc big bore kit will fit the following models:
Honda:
-CRF50 and CRF70
-XR50 and XR70
-Z50R 1982-1999
Lifan:
-50cc and 70cc Motors
Zongshen:
-50cc and 70cc Motors
All other 50-70cc Pit Bikes and ATV's with replica Honda horizontal motors
THIS KIT DOES NOT FIT Z50 ENGINES PRIOR TO 1982! (Piston/Cylinder Kits are coming soon for the "short rod" pre-'82 motors!)
Increase your displacement on 50cc models, or freshen up your tired 70cc top end. Get the RPM's you can't achieve with a restrictive 50cc cylinder head, or replace your damaged 70cc head. This is the only kit with a 47mm ALUMINUM cylinder on the market. Aluminum cylinders dissipate heat more efficiently and weigh considerably less than the cast iron competition. This all-new completely assembled cylinder head uses a 23mm intake valve and 20mm exhaust valve similar to the XR/CRF70 head. The cylinder heads will include all engine covers EXCEPT the round cam cover. You will simply re-use your stock one. A high volume oil pump is also included for the 50cc models. Individual kit components are available upon request! Email me if you are just looking for a 47mm cylinder/47mm piston kit/70cc top end gasket kit/or anything else you see. Replacement parts are in stock if you need them.
This Kit Includes:
-47mm piston/cylinder kit (including rings, wrist pin, and circlips)
-47mm complete top end gasket kit
-23/20mm valve race head. (assembled with all covers minus the round cam cover)
-High Volume Oil Pump (recommended with use of any race head on 50cc engines)
Link to product on site - Ahp Minis
Individual component prices:
72cc gasket kit - $10
47mm piston kit includes rings, circlips, pin - $25
47mm Aluminum cylinder - $40
HV Oil Pump - $19
Assembled race head, 23/20mm valves - $75
Contact and paypal - mark@ahpminis.com or 610-417-2533