A: Hard starting when the engine is warm could be caused by several problems, but the first thing to check is the bike's electrical system. The resistance in an ignition coil increases as the unit's temperature rises, and the 21-year-old coils in your FJ might not be up to the task of lighting the fire in a hot engine. If that's the case, upgrading to a new battery type probably won't do much except reduce weight. Rather than throwing new parts at the problem, take a methodical approach. Have the battery load tested. If it's even a quarter of the age of your bike, it may be faulty. If it checks out, have the coils checked next. If all the electrical components are up to spec, turn your attention to the carburetors. The FJ1200 isn't particularly sensitive to carb synchronization, but if one or two are far enough out of sync, you could get hard starting. A leaky airbox will have the same effect, as will air leaks anywhere upstream of the engine. Check the boots between the airbox and the carbs, and inspect the carb manifolds for cracks.