1. Pull the carbs, take the bowls off and see what your main jet and pilot jet are. If your really feeling inquisitive pull the slide and needle. You are adjusting the mixture screw, not the jetting.
2. The "VFORCE 3 thingy" are your reeds. Are your filters clean?
3. Trans oil wont have any effect on the spark plugs fouling really. Get yourself a good premix (klotz, maxima, spectro, etc...) I always mix @ 32:1