Lipos seem to be "flat"...what could be the cause?

[GYG]

Hey guys,

I'm a little bit stumped with my setup...I'm running a 2 week old E-Revo with a Tekno Neu 1515 1.5D, MMM, and Tekin 3400 23C lipos.

Here's the problem...I had a similar setup in my old converted Revo...same esc, same batteries, but a regular smooth can 1515 1.5D. Since I've converted, I picked up the Tekno Neu, and while low end seems strong, the truck just feels "flat" on the top end...like it just doesn't want to keep pulling. The packs (4 of them) are roughly 5-6 months old, and have never been pulled down to the 12.6V 4S cutoff I have programmed into the MMM.

I've redone all of my wiring from the esc to the motor, and from the esc to the battery. The only thing I haven't replaced are the Deans plugs.

The truck feels flat with all 4 packs in any combination, so I don't think it's the packs that are falling off. I'm starting to think there might be an issue with the motor? It's got maybe 10 full runs on it. I've tried different gearing...22/58, 17/58, 22/64, 17/64, 22/68, etc and it just doesn't seem "alive" anymore.

The MMM is set for 0 current limiting, and has been recalibrated several times to make sure I'm getting 100% fwd throttle.

I guess I'm just looking for some ideas that I might not have thought of so far...maybe I should replace the Deans? Maybe somehow all 4 of my lipos have lost power? Is there something I can check inside the motor to make sure something hasn't gone awry in there? The truck is brand new like I said, and there's no binding in the drivetrain...I'm a bit lost at the moment.

I'd appreciate any ideas you can throw my way...