Jake, cleaning the tank is on the agenda.
Where is this overflow valve yout mention?
I'm suspecting it may be getting too much fuel injected, thus causing the rough idle and smoke. However, smoke is NOT black. Once I rev it up or go on down the road, it does just fine. Only gives problems on idle.
Also, the fuel odor is awful when it takes the spells.
Someone mentioned checking a valve (or something like that) on the back of the fuel pump, but as I understand it it only is on Turbo's. Mine is not a turbo. Thanks Jake, Phill