Fuel Tank Selector Switch Changed

[VileZambonie]

I lengthened all the rubber gas lines before I put the new tank in to make the installation easier.

This is most likely your problem. One of the hoses is probably kinked.

[rainman15]

The fuel hose for either tank will work if I connect it to the input on the switch valve for the left side. When I have either connected to the right side input it runs a minute or so then slowly dies as if its out of gas. 

[Mule man]

The same thing was happening to me after a new selector valve and 2 new tanks. I would run out of gas going up hills on the right tank.  I finally changed the fuel filter and fixed it.  It would run on the right tank, but going up hill or accelerating it would run out.  I think it had just a little more volume from the left tank.  I also throw those little rubber backflow valves away on the incarb filters.  Just an idea.  It fixed mine.  Good luck.  I had a few 4 letter moments.

[rainman15]

I also throw those little rubber backflow valves away on the incarb filters.  Just an idea.  It fixed mine.  Good luck.  I had a few 4 letter moments.

It sounds like you and I have the exact same issue.  Ok, I replaced my fuel filter in the carb, but what / where is the backflow valve you are talking about?  My next guess was to replace the fuel pump, thinking maybe it is getting weak. 

[Mule man]

The inline fuel filters I buy have a little rubber valve inside the filter to keep fuel from draining out of the carb.  I always pull the rubber gasket off the inlet side (which pulls the valve out) and cut off the valve, and then put the rubber gasket back on. I believe it reduces flow.  I tinkered with mine for months before I found the problem. I thought there was a vacuum in the tank, weak pump...Did you look inside the filter when you removed it?  Mine had rust, but it was not completely filled.  The fuel flow was just restricted.  It ran fine on the left tank.  I assume there was, for some reason, better flow from that side.  Good luck.

[txchainsawgogi]

Same thing just happened to me, except I got rid of the second tank. The fuel line from the sending unit to the metal line had too much slack (1 inch) and would suck in on itself when pumping, slowly killing the engine.