Mirage drive - clicking and popping noise

I bought a used 2015 hobie revo 13.  I finally got to test it out today and noticed loud popping sound emanating from the drive when under load. It's not fins hitting the hull...more like rock lodged in gear sound.  I googled the symptoms and it says to tighten the chain bolts and sprocket area.  I did and the sound is still there.  Doesn't appear to be skipping gear either.  Any clues to what's happening?

The cables should be pretty tight with just a little deflection when pressed on from the side , but not enough to bind.  The teeth on the sprockets are a tight fit to the chain as it is and if the chain catches the edge of the sprocket it can make that popping sound.  You might also want to take the chains off and take a look at the sprockets themselves and see if there are any missing teeth or abnormalities on them. 

Thanks Insayn.  I did as you instructed and the drive moves like butter.  I made some few other modifications to my revo and get ready for the tournament.

I especially like how my dry box turned out for the battery.  Use some Yakima bar clips to attach it to the mast pole.

Tried my best not to drill new holes.

Looks good mak are you running the wire for the transducer down the grooves on the bottom of the kayak ? Where's the transducer mounted ?

Thank! Hobie has built in transducer mounts underneath the boat.  It was a reach to thread the nut of the connector but eventually I got it installed.

That happened to my paddle once....