I have 2001 500 efi's
Only when running I get a faint engine pop. Not even sure which motor. Happens in frequently but happening more often. Started running regular fuel from premium. Added some startron. Any ideas? Fuel or electrical?

Any help appreciated

Im having same problem with port motor in sonic but mine gets worse and looses rpm until i come off plane and let boat settle. Was told from a friend on here that its the screen or high speed electric fuel pump in the cool fuel .Also check your plug wires cap and rotor spay with some water at night and check for arcking

Just changed the fuel water sep and put in startron, ran to the sea side bridge and back with no pop.