I have a B5m with a Hobbywing 120a 3.1 esc and a reedy 17.5 brushless motor. Reedy servo and 5200mah battery. My problem is I get throttle cut out at higher speeds. I'm not losing steering but throttle. It seems to be fine if I constantly feather the trigger and not hold it down constantly. Though, sometimes if I keep it down it cuts out and then comes back after a second or so. Motor does not seem to be getting hot and it happens as soon as I turn on the car and drive off.

My radio is a second hand DX3S that is pretty old it seems. I've changed batteries in the receiver and tested on a full charge of the battery. The battery is second hand as well. So my question is does this sound like a power or battery issue? Or, is this a radio or esc issue? Any help would be great seeing as this is my first RC car.

Have you tried re-binding the radio to receiver, and recalibrate the esc, how about a spektrum capacitor
So when this happens are you going straight as with spektrum if it loses signal it would go straight ahead, depending on what the fail safe is, but you could check that, hold the car off the ground and shut off the radio while the car is on, how old is the battery and does it do it right away after a full charge??
Looking to help you out.

Reading it again, do you have another battery pack to try, sounds almost like it's going into voltage cut off

The battery was second hand with the car. It took a full charge but took forever to balance charge it. It happens when going straight but I still have steering control. The battery was chwrgeswhen I tried it. I recalibrated the radio to the esc and it didn't seem to help.

Maybe try a new battery and capacitor on the receiver? Would that go in the AUX plug on the receiver? Thanks again. Enjoying it so far besides this issue.

Check your sensor wire and sensor board as well. I had a similiar problem in the past and it was a bad sensor board on the motor.

Yes the capacitor will go into any extra slot in the receiver, so by chance did you get a program card for the esc?? As you mentioned that you rebound the esc to the radio, but did you rebind the radio to the receiver ?
I am guessing this is the only battery you have as well??

It keeps sounding like the battery is the problem.

[QUOTE=Troubles Dad;14950086]Yes the capacitor will go into any extra slot in the receiver, so by chance did you get a program card for the esc?? As you mentioned that you rebound the esc to the radio, but did you rebind the radio to the receiver ?
I am guessing this is the only battery you have as well??

Only battery but I was planning on picking up another one. Any suggestions?

I don't have the binding pin for the radio. I believe I need it to bind it again correct?

Also, if it's easier I can pick up another radio if I can get a decent beginner one for around $200.

I will add this.... I can pick up the car and pull the trigger to full throttle and it stays on. Not sure if that makes a difference or not.

[QUOTE=JimBonks;14950111]If you do go for a new budget radio, you can't go wrong with the Futaba 3PV.

4PLS is a great radio as well, more features and probably a little easier to program.

My battery choice would be SMC, price and quality are about as good as you can get, so what receiver do you have, some of the spektrum receivers had a button to push down, and wished you where closer, it is so hard to diagnose problems without being able to touch them.

Their are a lot of decent radios out their, currently I have the spektrum dx4s and the airtronics mt4 both well under 200 dollars, have yet to use the Futuba radio.

It's the DX3s with the sr301 receiver. My main concern is ordering a new radio and battery and then having a esc or motor issue. With my limited knowledge it does not seem to be an esc or motor issue but a power or radio issue. Just hate to order a new radio and have the same issue.

Should I pick up a new battery and maybe a capacitor and try that first?

Honest opinion, buy a battery, unless you know someone that has one you can try, do you have a local hobby shop, they may have one you could try as well, and you can always use extra batteries, I would recommend up to a 5,000 mah battery pack, as I can run upwards of 25 minutes on a 4,000 mah battery pack and the more the mah, the more it will cost, also get the biggest C rating you can, it keeps the voltage higher thru out the run

I do have a local shop. Just as an FYI the charger I have can check voltage and after about 10 or so minutes of driving the voltage was down to about 3.4 on a 5200 mah battery. Is this normal?

I too have a Xerun v3.1 I find throttle cuts out when your ESC is too hot, motor is heat soaked, battery is low, battery doesn't have enough C rating.

I think the more real culprit is your battery not being able to put out enough amps for when you are pinning the throttle. You get maximum draw when your trying to move the car from a stand still. A higher C rating battery, 50C or higher will help.

Also when my batteries are near the voltage cutoff I will periodically get a blip in my throttle when I am pushing the motor hard. For instance, from a stand still or right out of a tight turn.