Stuck gas cap

[PONDGUY]

'83 100rs. The cap threads appear,feel, seized in the tank. The cap is not locked, the lock mechanism works, but the cap will not come loose.
Tried some penetrating stuff but realized that if you are trying to keep gas from coming out then trying to get penetrating stuff in is a lost cause.I'm sure somewhere this "difficulty" has been gone over ad nauseum, but I could use some hints on how I might get this loose in the least destructive way possible. There is some movement of the cap left/right but then it fetches up tight and feels as if I gave any more wellie I'd have part of the cap in my greasy hand and the thing would still be stuck

 

[England-Kev]

Pour some hot water over the tank from a kettle, then try pushing down on it as you undo it.

 

[nick.ct]

I seem to remember that when I bought a tank for an Airhead (flush fitting style), it came with a cap that was locked and had no key and I just pulled it hard and it just popped out, seals gaskets and all. I put a strap through the flip up handle to get an easier pull on it.

Nick

 

[Kenny]

I seem to remember that when I bought a tank for an Airhead (flush fitting style), it came with a cap that was locked and had no key and I just pulled it hard and it just popped out, seals gaskets and all. I put a strap through the flip up handle to get an easier pull on it.

Nick

That's the way to do it

 

[PONDGUY]

SIEZED GAS CAP

It's off. Many thanks for the suggestions. A little penetrating oil and patience, but on examination I think it was the gasket causing the problem. The threads seem to be a rattle piss fit, lubed 'em anyway