Gas fumes. Need some ideas...

[1972GT-351]

So I have had this 73 Mach-1 for the last 30 years. In the last 3 years after a nice run the garage ends up filling up with gas fumes. I have never found any leaks. I have changed all rubber gas lines, rubber vent lines, gas tank, gas tank to filler neck seal, metal vent line from charcoal canister to air cleaner with no help.

Anyone else have this issue? Any suggestions?

Thanks in advance.

Rich

[Don C]

Gas cap gasket?

[1972GT-351]

Hmmm. I do have the pop open gas cap. The spring tension is good. But I may put another one on for an experiment...

[MotoArts]

Carb float level high?
Porous carb body, draining into or onto intake?
Used to have that problem with the Tiger.

[midlife]

Gas tank has pin hole leaks on the top in the trunk? Poor seal from the filler cap to the tank?

[Flatback72]

Rusted tank joining seam?

I had a 70 Mach 1 that had a slight leak in the seam, it leaked enough to smell, but not enough to be obvious as the gas would evaporate as it leaked out. Also, when the gas got below the seam level the smell would go away, which made troubleshooting even more difficult. Took me 6 months of searching before I found out what was happening...