Help with fuel tank venting Options

[flipb]

I replaced the seal under the fuel cap a few years ago, and I recently realized that the fuel tank is forming an airtight vacuum as it drains. In fact I recently burned out and replaced a fuel pump, and in hindsight, I realized it probably burned out due to pulling against vacuum pressure in the tank.

When I remove the gas cap after a drive, there is a very noticeable suction.

My question is: What's the proper routing for charcoal canister and fuel tank ventilation? I'm running carbs on a 2056cc engine. Photo here of the canister... the other end of the hoses seem to be loose/uncapped in the engine bay but could be kinked/blocked somewhere.

[bbrock]

Definitely hook up the vapor lines like Clay says but I think your problem is more likely here. That tube runs from the filler neck just below the fuel cap to the expansion tank. If that is clogged or kinked, the tank won't be able to equilibrate pressure with the expansion tank and atmosphere.