A failing or damaged spark plug could weaken the engine, limiting its performance or keeping it from starting altogether. The spark provided by your motorcycle's spark plug is responsible for igniting the flammable mixture of air and fuel within the engine. Video answer: What is motorcycle ecu flashing and what do you get. What happens when a motorcycle battery goes out?.What happens when a car hits a motorcycle?.What happens when your motorcycle gets stolen?.If a motorcycle chain breaks while riding, you will immediately lose the driving force the engine applies to the rear wheel and your motorcycle will lose power. ? What happens when a motorcycle chain breaks? What happens when you drop your motorcycle?.What happens when someone steals your motorcycle?.What happens when my motorcycle permit expires?.Every time you let your battery die, it causes some permanent damage, making your battery lose some of it's ability to charge fully. If a motorcycle battery is not used and just sits, it will lose it's capacity to power your motorcycle. ? What happens when a motorcycle battery dies? What happens when insurance totals your motorcycle?.What happens when a motorcycle runs lean?.What happens when a motorcycle regulator fails?.The constant beam of the sun is ruthless on motorcycle gas tanks. There are a lot of things that can go wrong when a motorcycle sits, but some of the main things that happen are a fading/peeling gas tank, damaged seals and gaskets, drained battery, condensation build up, and rust.