How to "Pop a Cap" on a tank that has been sitting

... for years?

I've got a key, but it doesn't do much. there is something inside the tank. Valve is closed and the whole thing is sealed, not leaking.

Wondering the least damaging way to get her open so I can make it usable again.

Any advice is appreciated. Thank you.

Lots of WD40 in the lock mechanism itself over a few days ?

OR

Turn tank upside down & fill with old engine oil through the fuel tap hole.......that should lubricate lock & mechanism from inside ?

Pete F

I've gone the WD40 route and also coated the key with bearing grease and worked it around in there.

Not knowing the condition of the liquid inside (approx. 2/3rds full...) I haven't cracked any seals yet, hoping that since the seals are intact, it won't be too bad.

I was pretty muchat the point of drilling out the lock mechainsm or the hinge pin if I could get to it.

Mine didn't want to open when I got it either but after wd-40 and putting a little pressure on the cap itself then gentley working the key back and forth it finally popped open. I wouldn't drill it just yet, I would just keep soaking it and try it every once in a while.

A locksmith may have some suggestions, or tools to do this task.

Hey, here is an odd question perhaps.

IS there a different key for the Gas Cap than the Ignition?

The key for my '88 EN450 is approximately 12mm longer than the KZ1300 key, and seems to fit better.

Wondering if perhaps I don't have the correct key.

How long is the key supposed to be?