Fuel Cap Gasket replacement

[PandaSal]

Hi all,
Just brought home my spyder last weekend. Realized right away gas fume smell in my garage, first obvious to me is that the fuel cap doesn’t seal tight. Anyone know where I can order replacement gasket? This was Thunder ranch kit, but not sure that matters when buying these small parts.
Thanks,
Sal

[Larry Jowdy]

You're better off going to your local auto parts store and buying a sheet of gasket rubber and making your own gasket. Another issue that's forgotten by most new owners of Spyders is the fact that the car isn't fuel injected but rather has 2 carburetors. The Carburetors hold gasoline in their fuel bowls and therefore will smell of gasoline. Fuel Injected engines are sealed and as such, no gasoline smell (unless there's a leak)

[albaran]

We get spoiled by modern cars which have sealed fuel systems. I have two carbureted cars, the Spyder and a MGA. They both will have a slight smell of gas when I come home from a trip. The smell is probably, as Larry says, the gas evaporating from the float bowls. I would be careful about sealing the gas cap too much because they are supposed to be vented to allow air into the tank to replace the fuel that is being drawn into the carbs.

[danstern]

Stick your nose near any 356 and there's a slight smell of gas. That said I had a similar stronger problem. First I tightened the spring inside the gas cap to make sure my gas cap rubber (which had no tears) was sealing. Then I resealed the sender. Then an extension for the exhaust pipe. Finally I found a slight crack in the tank near the sender and had it welded. (A Gas Co. natural gas sniffer was instrumental in finding the crack.) The car now has just the normal carb car odor.

[PandaSal]

Thanks for tips everyone. This being my first classic car, not familiar with what “normal carb car odor” vs being concerned about unsafe level of gas smell. I ordered 1/4 sheets of rubber on Amazon. Will plan to make my own new gasket to replace fuel cap gasket as it’s not closing/sealing very well. I can still depress gas cap about a quarter inch even after it’s locked

[DannyP]

That's what it's designed to do. There isn't usually a vent hose on Spyder tanks, the venting is done through the cap via a spring. As the fuel level drops, air is let in to fill the space. If air couldn't enter the tank, your engine would starve for fuel as the pump couldn't work against the suction. Conversely, if the fuel expands the vapors need to be let out. This is part of the smell, along with the fuel that evaporates from the carbs.

[PandaSal]

Thanks for the info Dannyp!

[albaran]

Otherwise, you might be going down the road one day when the car mysteriously comes to a stop. You get out to check what could be wrong. You open the gas cap and you will hear this loud whoosing sound as the air rushes into the tank to fill the vacuum in there. Don't ask me how I know this.

[DannyP]

That's funny, Al!

[RBP]

On my TR the cap didn't seat so it wouldn't seal and my garage stunk like gas. I fixed the cap spring and seal so that it seated tight. It then caused the tank to vacuum a bit so I drilled a small hole through the metal plate to allow some air. Problem solved no more issues.