Jerking / hesitation under acceleration

The bike bogs down, coughs, hesitates, or misfires as you accelerate: the rise in revs isn't smooth and consistent. The engine isn't getting its fuel or spark right when you open the throttle, and the approach is to isolate where things are getting stuck — fuel supply, ignition, intake, or electronics. The carburetor/injection distinction comes first, since it rules out certain causes right away. On a carburetor, jerky acceleration often comes from partially clogged jets (flat spots on acceleration, sluggish pickup) or from stale fuel/water in the tank (misfires). On the ignition side (applies to both types), a worn spark plug or a damaged lead/cap lets the spark fire intermittently, especially under load at high revs. A parasitic air leak in the intake leans out the mixture and creates jerkiness, especially at low revs and small throttle openings. On a fuel-injected bike, a dirty sensor or injector causes jerkiness, sometimes with the check-engine light on. The distinction sharpens based on the rev range where it happens (low revs = air leak/carburetion; high revs/load = ignition), how old the fuel is, and whether the warning light is on. Urgency: jerky acceleration isn't dangerous in itself, but it ruins the fun, can catch you off guard (a jerk mid-corner), and signals an engine that isn't running right — worth diagnosing, starting with the simple, free causes (fresh fuel, spark plug, checking for air leaks) before pulling the carburetor apart or plugging in a diagnostic tool.