RX8 1700 truggy issues

I am running a 8T 2.0 with the Losi conversion kit and Tekin RX8 1700 truggy combo. The batteries I am using are a Neu 5S 5500 25C and Zippy 5S 5000 25C. I talked to Randy and he suggested using a 16 tooth pinion. I bought this combo in the winter and used it indoors with great success. I went outdoors last night for the first time and was having issues. It was cogging at low speeds so I put an external capacitor into the receiver and it cleared it up. Last time I did this with a Mamba Monster it worked for a couple of races and then the internal ESC capacitors blew in the Mamba Max. I am going to have the same issue? Any advice would be greatly appreciated. This is the newer ESC(Red Heatsink) and newer rotor(Aluminum Cap). The outside temp was 75 and after my fix the ESC was 110, motor was 175, and the lipo was 115 after a 10 min run on a track.