hello, i have a 2012 foreman 500 and i use to ride a few times a month but i havnt been able to ride much latley. i tried starting it up a few days ago and it has a very loud backfire when i try to crank and give alittle throttle. the battery died a few months ago and i got a new battery and it ran fine and started right up after that. but i cant get it to start up. it will turn over but i was wondering if it was with the plugs needing to be changed or need to pull gas out and do a full service.