Fuel concerns bike not running well

[toof]

According to my spark plugs the front cylinder is running good but the rear is running to rich i have a S&S motor with a S&S Shorty E carb. what does this mean? the other day i wormed it up for about 10 to 15 min and went for a ride at first it ran real good(great) after about 10 min on the rode it started to spit and spuder. i live in NY so the temp out that day was about 35 degrees out.The bike is new to me i don't no to much about it and I am trying to learn all i can. ANY ADVICE IS HELPFUL AT THIS POINT!!!!!!

[Renegade FXRS]

If it were the fuel it would assumingly affect both cylinders. I would start with the ignition but would look at the coil first. I have seen coils get hot and loose spark and cause poor running and affect a specific cylinder. Just a thought!

[toof]

cool thanx im looking in to it