cover seal. The seal prevents leakage of lubricating oil from around the area where the crankshaft pm trudes through the cover to the outside of the engine The ignition distributor usually has two basic factions. First, it closes and opens the electrical cir- cuit between the battery and the ignition oil. The second task of the distributor is then to direct each high voltage surge to the correct spark plug at the correct instant in the engine cycle by the distributor rotor cap, and secondary wiring. The oil purnp usually mounts to the upper crankcase area of the block. It is actually part of lubricat ing system. Its function is to draw lubrieating oil from the pan and force it to all the moving parts of the The fuel pump is to transfer fuel from the fuel tank to the carburetor. This pump is actually parts of the fuel New words dominant ad.文配的,统治的 轴颈 直径 内径 displacement n.排气量,气缸1作容积 fication n.参数 stroke n.行程,冲程 intake 1.进气 exhaust v.排气 alve n.气门,阌门 verla n,进气门和排气门同时打开的时间 throttle n.节气门 horizontally ad.水平地,平卧地 ntstrYoIr 贮油器,油箱,蓄电池 cireuit n.电路,冋路,循环 carburetor n.化油器,汽化器 Phrases and Expressions cylinder block气缸体 spark plug火花塞 compression ratio H缩比 ignition distributor点火分电器,分电器 conbustion chamber燃烧室 气缸体 Bottom dead Center下止点