Bl Conversion probs again

[Thunderbruiser]

so i took my bl mantis out the track tonight...and well somethings up it just cogs and get hot instantly both motor and esc now before..eg last weekend the car ran fine until one of my batt connectors came a loose now does this have to do with the controller or the motor? i upped the batts from 2x2s8000mah to a 2s&3s 8000mah for a total of 5s...what do you think the prob is? i've smelled the esc and it doesn't smell burnt..but can get pics up tommorow for all you guru's to look at