How the hell do I get a stuck fuel cap to open lol?

[RickTaff]

zxr 750 1991. Fuel tank is off the bike, no fuel in it. Key will go into the barrel fine, but will only turn 45 degrees to the right, will not go any further

Have shot wd40 down there, wiggled the key. Pushed down on the key while turning - nothing -... stumped

any ideas would be greatly appreciated

[Riejufixing]

Try it upside-down or at some other angle? Leave it to soak with some solvent in (e.g. petrol) and jiggle the key about while gently turning? Drip some solvent in and blow it out with air then try again?? Swear at it and repeat?

[jeffyjeff]

Maybe the lock is working right. After years of storage, the cap and seal ring could be stuck shut. Try adding a pint of gasoline into the tank via the fuel line (that feeds the carburetor). Turn upside down to work the petrol toward the cap seal. Apply compressed air into the tank as you turn the lock and attempt cap removal. Be prepared for a burst as the cap opens.
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History shows again and again how nature points out the folly of men - BOC

[The Shaggy D.A.]

Can't you unbolt it from the tank?
____________________
Chances are quite high you are not in my Monkeysphere, and I don't care about you. Don't take it personally.
Currently : Royal Enfield 350 Meteor
Previously : CB100N > CB250RS > XJ900F > GT550 > GPZ750R/1000RX > AJS M16 > R100RT > Bullet 500 > CB500 > LS650P > Bullet Electra X & YBR125 > Bullet 350 "Superstar" & YBR125 Custom > Royal Enfield Classic 500 Despatch Limited Edition (28 of 200) & CB Two-Fifty Nighthawk > ER5

[The Shaggy D.A.]

Can't you unbolt it from the tank?
____________________
Chances are quite high you are not in my Monkeysphere, and I don't care about you. Don't take it personally.
Currently : Royal Enfield 350 Meteor
Previously : CB100N > CB250RS > XJ900F > GT550 > GPZ750R/1000RX > AJS M16 > R100RT > Bullet 500 > CB500 > LS650P > Bullet Electra X & YBR125 > Bullet 350 "Superstar" & YBR125 Custom > Royal Enfield Classic 500 Despatch Limited Edition (28 of 200) & CB Two-Fifty Nighthawk > ER5

[MCN]

Can you unbolt it from the tank?

Asking for a friend.

Pour a boiled kettle over it. Maybe not bubbling hot. Not all at once.
Heating the phuquer may soften the rubber sealing ring and then it might move. It may take a minute or more to heat up the cap, tank neck and seal.
Then either get a new cap or try some silicone grease on the seal of the old one.
Silicone won't harm the rubber seal. Oil based grease might.
And never use an oil based lubrication with a condom either. 😉
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[Robby]

Is this a bike that has been standing for a while?

If so, the cap locking mechanism is likely to be covered in loads of alloy corrosion - white powdery shite.

Lots of WD40, keep working the key. You will gradually scrape it off by operating the lock.

[pepperami]

I’ve said this before and I’ll say it again.

Compressed air and solvents/oils/fuels and enclosed spaces (petrol tanks) are a very dangerous mix.
You may have no problem for 999 times, the next time BOOM!


Please be careful!
____________________
I am the sum total of my own existence, what went before makes me who I am now!

[Kawasaki Jimbo]

I had this problem. You can't remove the cap surround because the bolt(s) holding it to the tank are under the cap. WD40, etc. didn't work and I escalated up to brute force, starting with a rubber mallet hoping to break the corrosion (unsuccessful), then on to narrow-nose pliers around the base of the key, and turn. The key survived with a slight twist but it's helpful if you've got a spare. Last resort though.

When it freed it was apparent that the corrosion was in the latch. Applications of oils and solvents through the barrel wouldn't have reached there.

[RickTaff]

[RickTaff]

[RickTaff]

Finally done it! Relief

[pepperami]

[MCN]

[RickTaff]

[jaffa90]

Well full marks for
Kawasaki Jimbo