G22 New Batteries and Alltrax, Still Slow

[BradTX227]

I have a brand new set of batteries (6 x 8v U.S. Battery), a brand new 200amp solenoid, and I just replaced the burned out controller with an Alltrax XCT48400. The cart only hits a top speed of 12mph. This feels ridiculously slow, even for a stock cart.

I've tried switching between "4 pole" and "8 pole" speed sensor modes. It's already set at a speed limit of 6,000rpms. Turbo mode is on. Voltage under load seems to drop down to about 47.3 - 47.8 while driving, and later rises bac up and over 48v when parked.

Is this a sign that the motor needs replacement? Or am I simply lacking the correct settings? The motor is from "Electrical Motor Products". But because I can't find any information on it, I can't tell if it's factory or aftermarket. Either way, it's...definitely "aged".