Moffitt

I have a Spectrum 2.4GHz DX2 transmitter with Rec. and a Duratrax Evader St transmitter and rec. I have used them both with my Duratrax Sprint 1 Esc and they seemed both to work fine and all with Co27 Cobalt Stock motor and duratrax 3800mah Nimh 6cell 7.2volt batteries, but when I put my Lrp runner Plus reverse esc for my duratrax one it seems that it goes a good distance but sometimes acts up and the thing is my duratax one goes farther than the lrp one. Maybe it's fine and I need to get up higher onto something for it to go farther than the duratrax one, cause it's got more features than the duratrax sprint.

Argess

Sounds like excessive harmonics in the ESC output to the motor. You could try connecting a couple of small capacitors across the power lines to the motor.

I found this on the net. Maybe it will be of help:

The small disc capacitors (usually brownish orange in color) soldered direct to the motor leads at the motor chassis are noise suppression capacitors. The motor's inductive load is electrically noisy. The capacitors prevent electrical noise propagating back to the control electronics.

Brushed DC motors are very noisy in this regard.

Electronic speed controlled (ESC) motors develop noise spikes when they switch phase. This can propagate back to the control ESC logic itself without the suppression capacitors.

Use a small mica disc capacitor of about 0.001 to 0.01 uF. Select a voltage rating at least 5 timeseven 10 timesthe battery voltage.

Try Googling "noise suppressor capacitor rc electric motor" for more info.