getting the most out of my amp's

Last summer I picked up the Bullet 770's packaged with the JL audio mono blocks. From the demo video those things screamed with that same set up. After installing it I am kicking myself a bit because the amps dont seem to provide enough power to the tower. I have 2 mono blocks and 4 770's.

I have been installing stereo's in my cars since I was a teenager. I have a basic working knowledge of the set up and install process. Honestly the car set ups were a bit more basic and didnt have as high end of componets.

I ran the new system piggybacking off the system that came with my boat. it came with a kicker 4 channel , dual batteries, perko, distrbution block etc.

The first thing that caught my attention was that the JL mono blocks' install manual stated that the in line fuse should be I believe 15amps. Seemed a bit low but since its supposed to be a super efficent amp i didnt think twice.

I have the gains sets at about 35-40% or so and show a constant reading of 14.1 volts on the dashboard. when I get much higher I get a bit of whine. what is a realsitic way to take this out? The wires are all short as possible and they dont overlap or cross.

I know the speakers have more untapped potential but am thinking the amps are big enough to give me more carry back towards the rider.

Im not trying to hear it from a mile away but hopefully at the end of a 75-80 ft line while riding.

I know I havent been super detailed here but any basic starting suggestions? I at this point dont have the money to go to a shop for them to tweak it so hope to fix it on my own or save up some cash to get a pro on it.

Thanks