My grandpa has an 01 sp500HO. Last week he started it up and it sounded like a harley. Its really loud and it backfires when you let off the throttle. He replaced the gasket in the exhaust but can't tell a difference. Any ideas on what it could be?

 

nobody knows?

 

There has to still be a leak somewhere,letting off gas like that tells its a lean condition.Check it from head to rear and i bet you'll find a leak.

 

thanks for the info