Welcome. What does it do when you hit the starter?
Did the old gas smell funny like varnish?
Only 4 months shouldn't be a major problem unless the gas was old to begin with. Only partially full is a larger problem because of condensation and moisture in the fuel.
If the bike turns over strong and no fire, then you need to check the spark plugs, air filter, and fuel filter. Engines need fuel, air, and spark.
Did the old gas smell funny like varnish?
Only 4 months shouldn't be a major problem unless the gas was old to begin with. Only partially full is a larger problem because of condensation and moisture in the fuel.
If the bike turns over strong and no fire, then you need to check the spark plugs, air filter, and fuel filter. Engines need fuel, air, and spark.