No, not all motorcycles use timing chains. The method of driving the engine's camshaft(s) and timing varies among different motorcycles, and timing chains are just one of the possible options. Here are a few different methods used in motorcycles:
Timing Chain: Many motorcycles use a timing chain to link the crankshaft and camshaft(s). The chain is made up of interconnected metal links and is driven by the crankshaft. Timing chains are durable and require regular maintenance, such as tension adjustment and occasional replacement.
Timing Belt: Some motorcycles utilize timing belts instead of chains. Timing belts are made of reinforced rubber and have teeth that mesh with corresponding gears on the crankshaft and camshaft(s). Like timing chains, timing belts require periodic replacement at specified intervals.
Timing Gears: In certain motorcycles, the timing mechanism consists of gears that connect the crankshaft and camshaft(s) directly. These gears are designed to mesh together and rotate in synchronization. Timing gears are often more durable than chains or belts and require less maintenance.
Timing Shaft: Another less common method involves using a timing shaft. The timing shaft is a long, slender rod that runs parallel to the engine's crankshaft and camshaft(s). It is typically driven by gears or chains and is responsible for transferring the rotational motion to the camshaft(s).
The specific choice of timing mechanism depends on factors such as the engine design, manufacturer preferences, cost considerations, and performance requirements. It's important to consult the motorcycle's manual or refer to manufacturer specifications to determine the type of timing system used in a particular motorcycle.