BSR Berserker servo problem
 

Hi everyone.

I've recently bought an used BSR Berserker. I stripped the servo gears and replaced it with another servo (Trackstar ts 900). On my second ride with the new servo, it started to behave weirdly.
It looks like the servo has not enough strength to move the wheels while they're touching the ground. But if i lift it up of the ground, the servo can turn.
Also, it stops responding and starts shaking (randomly).
I've already switched the servo connector to the throttle channel, but the problem remains. I can turn the wheels normally if the system is turned off.
I don't hear any unusual sound (like stripped gears). The only problem seems to be the lack of power...

I don't know if this can make any difference, but i went to run it without having my battery pack (4s) fully charged. This happened yesterday night and I've not been able to fully charge the battery and test it.
I have no other cars or TX/RX.
I'm a bit sad because I only used the car 5 or 6 times, replaced the servo and it seems that I'm going to have more problems.
What do you guys think? Could the problem be on the battery not providing sufficient power?
Could it be the new servo?

That servo should be strong enough for that vehicle. Yes, start with a fully charged battery and see if the problem goes away. If not, it could be the new servo. Do you have a friend with another car to test with?