My 6.5 was the biggest culprit of this. During the race it would just unsolder terminal A leaving the car stranded with steering, but no gas. The plugs are covered in solder so the connection is good. no dry joints!
re-soldered back on and sometimes it would do it again next race or sometimes it would go for weeks no problem. This happened indoors and outdoors where gearing was varied and the motor was never too hot to touch.
I don't remember this ever happening in my B44, just in the Cat and I think once or twice in the B4.
On disassembly of my 6.5 I noticed the A terminal was wobbly on the PCB and had burn marks around it. I figured this must be generating extra heat melting my solder. So the 6.5 was condemned. In went the 7.5. A few meetings later same thing happening. The A terminal again had a slight wobble to it. nothing at bad as the 6.5 though. then the 7.5 stopped working all together and won't run without wiggling the A plug. I don't swap the motors twice a week only every now and then so I wouldn't say there was excessive force on the terminals
In went my last V3 motor the 5.5. Again this happens! It's really starting to annoy me now having £150 of dead motors which I can only related to this problem not to mention the races I've had to retire from
Something that did cross my mind is I run the larger power cap of 4 capacitors on this LPF of mine. Could this possibly be related? I didn't buy it, it came with a 2nd hand SP LPF speedo I bought on ebay...
Until Taly this weekend it's always been terminal A, but on Sunday it was plug B
Any ideas?
I'm going to reinstall the standard power cap that comes with the speedo and see if that makes any difference.