Parkzone J-3 Cub Throttle Problems

[EagleOne]

Hello all:
A friend of mine has a Parkzone J-3 Cub and is having problems. I have agreed to try to help.
When the throttle if pushed full forward rapidly, it runs but then suddenly shuts down. If you take it slow, it will go to full throttle and run with no problem.
Any ideas? He is using the stock Parkzone 3-channel Digital Proportinal FM Controller.
I have tried everything that I can think of with no success.
Thanks for any assistance.
D. Mildfeldt :)

[aeropal]

I have tried everything that I can think of with no success.
To avoid suggesting what you have already tried, what does "everything" include?

[hpi Pro2]

Maybe the esc is going, just my thought

[EagleOne]

To avoid suggesting what you have already tried, what does "everything" include?

You were absolutely right, it was misleading when I said everything.
I checked the output from the control unit (oscilloscope) and all servos seem to be working. Did not pull the control board out of the unit, a little hard to get to.
Does that help any?

[aeropal]

Possibilities:
Unbalanced battery . . slow charge to equalize individual cells.
Bent prop shaft binding in gearbox or defective "shorted" motor drawing excessive amps and causing the motor controller to "see" the voltage cut-off point prematurely.

[miraclesailor]

I had a similar problem once. I was using a motor that was well under the amperage rating of the ESC. When I slowly turned it up it would go to full throttle. When I gave it the quick stick it would not. Later I discovered that the ESC worked fine with another motor. The original motor was drawing unusually high amperage. I guess it was just a bad motor. I threw the motor away as I did not want to think that it would work with another project then have the same problems come up again.

Try another motor and try a different battery pack. Do this seperately. If one works you want to know which.

Later,
Dan

[eddiebro]

I have a Parkzone j-3 tha does the same thing when the battery gets weak.