Engineered and developed by BBR. This cylinder retains skid plate mounts and includes: BBR aluminum cylinder, piston kit, exclusive BBR motocross-grind camshaft and gasket kit.The most reliable kit available. Runs great with stock carb or bolt on BBR's 18mm carb kit. Cylinder retains skid plate mounts. 52mm piston specially designed to work with your stock cylinder head's combustion chamber. Installation Note: This kit will not work with the Honda XR/CRF70 or other big port cylinder heads. It is designed for the tiny combustion chamber of the OEM Honda XR/CRF50 cylinder head.
The flat top piston dome will result in an extremely low compression ratio when combined with the XR/CRF70 type cylinder head. The result is a motor that makes less horsepower than stock.
BBR Does not currently make a big bore kit for the XR/CRF70. The item "BBR Motorsports 88CC Big Bore Cylinder Piston Kit With Cam Honda CRF50F & XR50R" is in sale since Monday, January 9, 2017. This item is in the category "eBay Motors\Parts & Accessories\Motorcycle Parts\Engines & Engine Parts\Big Bore & Top End Kits". The seller is "americanclassicmotors" and is located in Zieglerville, Pennsylvania. This item can be shipped worldwide.