Ever since item pipe upgrades were added (since before b3e3019), using an Large Advanced Motor in an item pipe only transfers 64 additional items per cycle (60 ticks) instead of the expected 128 items.

The other motors transfer items at a rate appropriate for their tier:

• Basic Motor: 2 items/cycle
• Large Motor: 8 items/cycle
• Advanced Motor: 32 items/cycle

Each tier of motor up to HV (Advanced) multiplies the transfer rate by 4. To make this pattern hold for the remaining tier (Large Advanced at EV), it should transfer 128 items/cycle instead of 64.