We've stood behind these products 100% since we opened in 2005. Best reviews received for a big bore kit hands down! Race Head, 88cc Big Bore kit, and 20mm Carburetor Performance Kit: All Years CRF50 & XR50 All Years CRF70 & XR70 88-99 Z50 91-94 CT70. It now has 25/22mm valves with better porting/flow.
We also kept the combustion chamber the same size and changed the angle of the valves slightly. This will really wake up your stock engine and is comparable in power to the much larger Chinese 124cc engines!!! Lightweight aluminum cylinder with steel sleeve - Cast in mounts on cylinder for aftermarket skid plates - Oversized cooling fins on cylinder for efficient heat dissipation - 52mm high compression piston with rings, pin, & clips - Head gasket kit and clutch cover gasket. High performance race camshaft (for the Race Head only) - Race Head Larger valves (now 25/22mm) and better flow for increased performance.Also has bigger cooling fins. Includes all necessary parts and comes assembled! The exhaust valve has been upgraded to stainless steel (21-4N material). Includes: 20mm carb, intake, heatstop, gaskets, mounting hardware/wrench, long adjustable throttle cable (does not work with stock throttle), and a angled dual layer foam air filter. Installation Note: DOES NOT WORK WITH STOCK THROTTLE! It will save a lot of time and effort if the oil pump is installed while installing the bore kit (requires cylinder removal). Replacement Parts: TBW0365 - Piston Kit. TBW0273 - Intake Manifold Kit. TBW0949 - Race Head & Valves Assembly. The item "88cc Big Bore Race Head Kit Honda Z50, XR50/CRF50 XR70/CRF70 CT70 TBW0936" is in sale since Monday, February 10, 2014. This item is in the category "eBay Motors\Parts & Accessories\Motorcycle Parts\Engines & Engine Parts\Other Engines & Engine Parts". The seller is "factorymotorsports-store" and is located in Riverside, California. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, Taiwan, South africa, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Bahamas, Mexico, New Zealand, Philippines, Singapore, Switzerland, Norway, Saudi arabia, United arab emirates, Qatar, Kuwait, Croatia, Malaysia, Brazil, Colombia, Antigua and barbuda, Aruba, Belize, Dominica, Grenada, Saint kitts and nevis, Saint lucia, Montserrat, Turks and caicos islands, Barbados, Bangladesh, Bermuda, Brunei darussalam, Bolivia, Ecuador, Egypt, French guiana, Gibraltar, Guadeloupe, Iceland, Jordan, Cambodia, Cayman islands, Sri lanka, Luxembourg, Monaco, Macao, Martinique, Maldives, Nicaragua, Oman, Peru, Pakistan, Paraguay, Reunion, Viet nam, Uruguay.