Welcome;
You got me. Perhaps some pictures would help.Youll need to post the pics at a photo site.I don't understand 2 tubes.Most tanks have a ingle outlet that goes goes directly to the carb.Might go through some sort of filter then to the carb.
I would be using the one with the filter.Those look like they are on a device of some sort,doesn't look like a tank.What happens to the unused tube.
Is the non filtered tube for some sort of recirculation system??
The pic. above is the carb. as stated there are two tubes comming from the tank and are connected to the inlets labelled inlet 1 and 2. What I think I will do is connect the tubes and try to start the motor. I think that the black tube with the filter should be the input. I sure the motor will start either way but I would like to connect the filter to the proper inlet so as not to suck any crud into the carb.