🔍 Key Concepts

• Two-stroke vs. four-stroke engine firing frequency per crankshaft revolution • How a rotary distributing air starting system must line up ports with each cylinder • Relationship between crankshaft speed and distributor disc speed so each cylinder gets air at the right crank angle

💭 Think About

• For a two-stroke engine, how many power (and thus starting) events does each cylinder have per crankshaft revolution? • If there are six cylinders, how many separate start-air delivery events must occur per crankshaft revolution? • Given those required events, what speed must the distributor rotate at, relative to the crankshaft, so that each cylinder gets one shot of air at the correct time?

✅ Before You Answer

• Be clear on how many firing events per revolution a two-stroke cylinder has • Confirm whether the distributor has one port per cylinder or reuses a smaller number of ports as it rotates • Make sure the chosen speed gives exactly one start-air admission per cylinder per required crank angle, without skipping or doubling any cylinder events