We have a double sink in the kitchen and we have snaked it using 15 and a 25 foot snakes but still not working. We have a 50 foot electric one now but it won't go in . Now what do we do ? We have also tried chemials and still nothing. Help

Does the vent for the sink exit the roof above the sink, or is there an aav? If the vent exits the roof, try using the 50 footer through the roof vent.

Good advice. Is this the only fixture that doesn't drain well?

Most mobile homes use aav vents which are found under the sink above the trap right before the line goes out through the floor they do fail but are easily replaced. This is basically a check valve that lets the
System breath air in but keep gases from entering the dwelling. It's a thought.thanks
Rojo