Thanks Dan. I'll take a look at the necks on the tanks .

A classic Mini fuel tank has a rubber grommet around the filler neck. Behind that, between the fender wall and the tank is a foam rubber donut around the neck. It holds moisture against he neck and produces rust pinholes that gradually turn into a sieve.

The remedy is to use POR-15 motorcycle repair kit, usually enough to seal a Mini tank. When I used it, it came with a strip if gauze to reinforce a patch. I used the gauze to seal the neck of my tank and cleaned and coated the inside of the tank. Here is a listing on Amazon.ca for the current kit. Ypu may find a better deal.

POR-15 Motorcycle kit

Obviously you need to drain and remove the tank. You remove the fuel level sending unit and poke something up the fuel line connection tube to push off the screen and remove it from the tank. If you don't the treatment will seal the screen. I did it a long time ago, but as I recall some people throw a bunch of stones, nuts and bolt etc. in the tank and shake it around to loosen any rust. Then you wash it out and dry it. Next step is to seal the sending unit hole and the fuel line. Then follow the kit instructions to clean, prep and seal the tank. Use an old gas cap to close the filler because you will need to tip the tank in all directions to do all the inside surfaces.

For the filler neck, coat the outside with the sealer, wrap the gauze around it and coat the gauze like you are making an arm cast (which I happen to be wearing right now).

Gas smell after filling duel gas tanks! Help! My garage always smells like Gas fumes. I try not to fill tanks all the way up. I also cant find any leaks, I just bought a new set of Gas caps from mini mania. Still smells bad. All lines at tanks are vented under car. I read that the monza caps seal better cause you get a complete new neck attachment that the cap seals too. Any thoughts?