Check that the tuning is proper, fill up the gas cylinders to the required level, install a new spark plug, clean the filters and recharge the batteries if required.
You should do a tune up. Start by filling the bike with fresh gas. The install a new set of plugs gapped to the right clearance. Check the timing to make sure it is spec. Finally make sure the filters are clean and the battery is fully charged.
Every engine needs three things to run air, gas, and spark. Make sure you air filter isn't clogged, the cylinder are getting fuel, and that you have a strong spark.
