Arduino MPU6050 Balancing Bot

Hello everyone, I am trying to build a balancing bot using an mpu6050, two geared dc motor, l293d and some batteries. Somehow, no matter how i tune the pid control, I cannot get it to balance. Am i missing something? The dc geared motor will stick and only spins when pwm value is 80. I used the following sketch.

Balancing_Bot.ino (4.31 KB)

I2C.ino (2.3 KB)

Geared? That doesn't sound good for a balancing robot. How big is the robot?

80 seems kind of high as a starting value. It's not unexpected for a geared motor.