1998 Challenger Carb mod


So I've been trying to get this boat figured out. 1998 SeaDoo Challenger 1800 twin 787's. I have spent endless hours and close to $3k on shops. Now I just figured out that my carbs have been modified. Needless to say this is my first boat. So apparently the chokes have been removed and a port added to inject fuel from an aftermarket electrical pump. Which appears to dump the return fuel back into the carb. Can anyone explain what they did or tried to do? Maybe how to fix it? Thanks in advance!
Usually the primer line tee’s off the return because it always has fuel in it,,,and it avoids using the ”line” so that there are no air pockets for the incoming fuel from the primer.