Dyno tests show more than 2HP gain with this kit. Fits ALL model year XR and CRF100's. High performance camshaft with HD valve springs.New rocker arms and adjusters. BBR Large fin, aluminum cylinder with steel liner. 58mm piston, ring set, piston pin & clips. Gasket kit including cylinder head and base gaskets. Fits 1981-Present year XR/CRF100's. The item "BBR Big Bore Engine Motor Kit 120cc Piston Cylinder Cam Shaft Honda XR100 CRF100" is in sale since Friday, February 26, 2016. This item is in the category "eBay Motors\Parts & Accessories\Motorcycle Parts\Engines & Engine Parts\Other Engines & Engine Parts". The seller is "americanclassicmotors" and is located in Zieglerville, Pennsylvania. This item can be shipped worldwide.