Anyone ever seen a Yale ERP060RBN with the Cableform accelerator box? I've got one with poor acceleration at the top of the pedal travel but seems to be ok with the pedal half to fully depressed. At the beginning of the pedal travel, it feels like there's a drag but the machine will coast along without any sign of dragging. The SCR hum doesn't change until halfway through the pedal stroke. Is there a way to check the accelerator box or anyone have any ideas as to the cause of the problem?