The bike won't start

You press the starter button and the bike refuses to start — either it stays completely silent, the starter spins without the engine catching, or you just hear a single 'click.' In nearly every case, the cause falls into one of four families: a safety interlock out of position (kill switch, side stand, neutral), a dead battery, running out of fuel, or a spark plug that's no longer sparking. More rarely, it's the starter motor itself or its relay, but that accounts for less than 10% of cases according to specialist shops. Before any costly work, follow the diagnosis in the order given: you'll rule out the free, trivial causes first, and only need to get your hands dirty as a last resort. If the bike has been sitting unused for several weeks, the battery is statistically the first thing to check — it can lose up to 1% of its charge per day at rest. If you just ran out of fuel and refilled, the plug may have flooded after a few repeated attempts.