23 year old tank with gas still in it...gas cap stuck! (Solved!)

[mikerophone]

New to me 82GS850LZ, can't turn the gas cap more than 45 degrees, it won't budge past 12 o'clock:



I sprayed PB Blaster, 3 in 1 oil and WD40 under the cap and into the cylinder as best I could, Jimmy'd/shook/tapped and pried underneath as much as I dared with a plastic stick while wiggling and tapping on the key. Let it soak overnight and put graphite and 3 in 1 oil in the key cylinder, still nothing tonight. Guess I need to let it soak longer...

Search didn't yield much other than this: http://www.thegsresources.com/_foru...uck-gas-tank-cap&highlight=stuck+gas+tank+cap

Google wasn't a whole lot more helpful, perhaps I should squirt some fresh gas down around the cap and let it soak? Obviously a propane torch would be a bad idea but perhaps the heat gun, but it is hard to get the heat down in the bottom of the neck ridge where it needs to be. Vinegar, PineSol or perhaps some acetone or other solvent carefully placed? The clear coat is already cracking and peeling around the striped edges and I'm sure the tank will need a vinegar soak, tumble with some bolts screws/nails followed by some POR-15 or Caswell coating once I finally get it open:



I'd hate to have to take it to a locksmith, tank is original and OEM key works fine in the ignition and seat tumblers. I guess if soaking it doesn't do it, I'll pop the petcock off or drain it on prime and refill with fresh gas or more lubricant, tip it upside down for a couple of days and try to free up the 2 little angled pins that hold it in that way. The cap is the standard one I see on all of m other GS's = spring loaded angled "pins" or tabs at six and midnight, they must just be gummed up. Don't want to drill it out and pay to get it re-keyed unless I have to.

Ideas/tips/tricks?

 

[Sandy]

Sounds like a good idea but instead of putting gas in it to soak why not try something that is more likely to lubricate the lock mechanism or help penetrate what rust might be in there.

 

[mikerophone]

Thanks Sandy - figured gas is a pretty good solvent - hoping that will dissolve the varnish that I am betting is around the cap and then spray in some lube/WD/ATF/oil whatever in next and let that work.

Just was hoping to not have to remove the petcock if I didn't have to. Guess the gasket wouldn't be too expensive to replace if I do.

 

[gearhead13]

My cap would get stuck from time to time.
I dont know if this would help, but I always pushed down on the cap with one hand while trying to turn with the other.

 

[Guest]

I'm thinking a bit of light rubber mallet persuasion, that may help knock some inner crud cake loose and allow the lube to penetrate a bit deeper.
You could shim the cap to avoid paint chips and even tap the key whilst inserted. Oh & patience.

 

[Sandy]

Just was hoping to not have to remove the petcock if I didn't have to. Guess the gasket wouldn't be too expensive to replace if I do.

Drain it threw the petcock and add your fluids through the gas gauge sending unit hole. Nice big reusable rubber gasket there.

 

[cornishgs]

pour boiling water on cap that might help.

 

[tatu]

Is it stuck tight or is there a bit of wiggle, I'm wondering if it's stuck on the gasket or whether its in the neck with built up crud and corrosion or whether the key is pulling back the tangs far enough, I would have thought 90 degree twist on the lock would be enough. (Have you tried pushing down on the cap at the same time?) if its stuck on the rubber gasket there might be a tiny amount of give in it help determine what it is. If you remove the tap/sender and peek inside you will know better what you are dealing with. Hot water sounds like a splendid idea, especially if you cycle it alternately, boiling water, cold tap.

 

[Brendan W]

When you turn the key from 10:30 to 12 o'clock does the cap lift a little or conversely if you push it down at the 12 o'clock position does the cap click shut?
Are you sure the cap hasn't been replaced and there is another key somewhere - mine is like that.
Check out the key for a tiny burr and try it slightly above the fully home position.
There is always the Bonham method. Moby Dick live version and two rubber mallets
A reciprocating power tool applied to the cap for a few minutes could vibrate things free. Say a jigsaw with the blade out on a block of hard rubber or similar.

 

[Guest]

Try SeaFoam Deep Creep.

 

[Frank Z.]

I'm thinking a bit of light rubber mallet persuasion, that may help knock some inner crud cake loose and allow the lube to penetrate a bit deeper.
You could shim the cap to avoid paint chips and even tap the key whilst inserted. Oh & patience.

This.

Had a similar problem with 12 year old gas in ZX tank. Locksmith said it's the latch that's gummed up, and suggested using liberal amounts of penetrating oil around/under tank cap (treating the tumbler itself won't do much, as it's the latch that's frozen), then tap-tap (x 1000+/-) with rubber mallet, while gently working key; essentially you're vibrating the crud loose. Took about 3 hours ?and 6 beers? but finally coerced latch to recede. Also, a good idea to have at least one more key cut, as the twisting effort will def lead to a bent/broken key.

Process may take a couple hours, or a couple days. Good luck!

 

[barnbiketom]

If nothing happens easily, try draining the tank thru the bottom, then use toilet bowl cleaner mixed 50/50 with water.
I REALLY like using the stuff to clean tanks, and with the caps installed when I clean them, they also come out like new, and never had a tank go bad.. pinholes/etc..
use the cheapest stuff you can get at Dollar General!!!

 

[mikerophone]

Wow - thanks for all the replies everyone. I work until 10PM tonight, so I'll be trying these suggestions tomorrow night and will report back.

My cap would get stuck from time to time.
I dont know if this would help, but I always pushed down on the cap with one hand while trying to turn with the other.

Pushing down doesn't seem to help, there is no give... I'll try some of these other ideas tomorrow night and then resort to Notz's/Brendan's Bonham method, complete with Zeppelin playing in the background!

I'm thinking a bit of light rubber mallet persuasion...Oh & patience.

This. I do get a little hasty at times, but the more I work on these old beauties, the more I appreciate and take my time. Haste makes waste, right?

Drain it threw the petcock and add your fluids through the gas gauge sending unit hole. Nice big reusable rubber gasket there.

Excellent suggestion! Forgot the sending unit gasket was rubber, have only had one off once ever.

pour boiling water on cap that might help.

I think this might be the ticket...

Is it stuck tight or is there a bit of wiggle, I'm wondering if it's stuck on the gasket or whether its in the neck with built up crud and corrosion or whether the key is pulling back the tangs far enough, I would have thought 90 degree twist on the lock would be enough. (Have you tried pushing down on the cap at the same time?) if its stuck on the rubber gasket there might be a tiny amount of give in it help determine what it is. If you remove the tap/sender and peek inside you will know better what you are dealing with. Hot water sounds like a splendid idea, especially if you cycle it alternately, boiling water, cold tap.

No wiggle at all, it only twists 45 degrees, 90 would do it. Pushing down yields no change, and yes, Hot then cold water sounds like a great idea.

When you turn the key from 10:30 to 12 o'clock does the cap lift a little or conversely if you push it down at the 12 o'clock position does the cap click shut?
Are you sure the cap hasn't been replaced and there is another key somewhere - mine is like that.
Check out the key for a tiny burr and try it slightly above the fully home position.
There is always the Bonham method. Moby Dick live version and two rubber mallets
A reciprocating power tool applied to the cap for a few minutes could vibrate things free. Say a jigsaw with the blade out on a block of hard rubber or similar.

Love Zeppelin, wish Bonham hadn't kicked it, truly one of the greatest drummers of all time, such a shame. It doesn't click or budge at all. The other key on the key ring is for the silly fairing that I'll inherit with the bike. I'll ask the interim owner when I pick the bike up next week, he is friends/works with the original owner who gave him the bike years ago and you'd think that he'd have sent him with the other key or mentioned it if there was a need to get a new one, but you never know. He does have to still get the title for me from him...

The cap sure looks original...I am thinking of ordering another key, but it's not worn (12k on the bike, key is OEM) and works great in the other cylinders, I'll try the slightly above home position too, but I've worked it in and out and back and forth for 20-30 minutes ad no change at all. I like your Jigsaw blade with a rubber bot on the end idea too, or maybe an orbital sander with no sandpaper on the pad...

Try SeaFoam Deep Creep.

If these other methods don't work, I just may. Sounds expensive though, I've never used the Deep Creep, but do buy the regular Seafoam for the intakes on my cars from time to time. Smoking out the neighborhood!

This.

Had a similar problem with 12 year old gas in ZX tank. Locksmith said it's the latch that's gummed up, and suggested using liberal amounts of penetrating oil around/under tank cap (treating the tumbler itself won't do much, as it's the latch that's frozen), then tap-tap (x 1000+/-) with rubber mallet, while gently working key; essentially you're vibrating the crud loose. Took about 3 hours ?and 6 beers? but finally coerced latch to recede. Also, a good idea to have at least one more key cut, as the twisting effort will def lead to a bent/broken key.

Process may take a couple hours, or a couple days. Good luck!

View attachment 38193

Agreed, and the beers will help for sure! That thing is NASTY!, I'll be sure to take a photo when I finally get this bugger off. Latch doesn't budge, even when tapping and lubing and inserting key over and over, even tapping on the key while turning doesn't change anything. I've been tap tap tapping away (Happy Gilmore voice here) and will continue to do so, complete with a custom concoction of penetrating oil, then soak, try again, try gas, Isopropyl, try boiling then cold water, then another beer, rinse, repeat... then I'll pull the sending unit if that doesn't work and try the above from below.

If nothing happens easily, try draining the tank thru the bottom, then use toilet bowl cleaner mixed 50/50 with water.
I REALLY like using the stuff to clean tanks, and with the caps installed when I clean them, they also come out like new, and never had a tank go bad.. pinholes/etc..
use the cheapest stuff you can get at Dollar General!!!

Another great tip, thanks. I've heard of people using toilet bowl cleaner, but never have, does it harm paint?

 

[Wingsconsin]

Patience and persistence will eventually win the day.
Use care and caution while trying to force the seal to open as damages caused by excess could ruin your day ...

 

[chuck hahn]

The only way to get a solvent to the two latches that grip the inside of the filler neck is to take out the sending unit and the petcock ( so said solvents dont ruin either one ) and dump in a bunch and set the tank on its top.

Now what solvent?? Cant be anything that will eat plastic as the bottom cap part of the cap is plastic. I would use 8% vinegar of it was me. Eats the crud and rust but will not harm plastics, rubber, or paint. Dump in half a gallon and set the tank on its top for a few days.

And vinegar is a great soak for the sending unit once its out. Cover it with vinegar and soak over night. Remove the cover and GENTLY clean the contacts with a soft tooth brush and Qtips.

EDIT...if youre gonna replace the cap..which is probably a good idea seeing the seals are hard to find..then some acetone will eat the plastic inside cap and the entire thing will fall apart in maybe 15 minutes or so. remove rest of cap. Be sure to not get acetone on the paint though.

 

[barnbiketom]

Another great tip, thanks. I've heard of people using toilet bowl cleaner, but never have, does it harm paint?

I don't know !
Of all the times I used it , I was very cautious, with gas cap on , and other assorted orifices plugged up, so I didn't get any on the paint.
I would think that yes, it might do something to the paint if you get it on there....? But honestly, the stuff works better than anything else I 've used from tumbling in the dryer wrapped in blankets ( no the wife was NOT HOME), to nails and gravel with solvent etc etc.

 

[chuck hahn]

Throw a bit on your worst neighbors truck paint and test it first....LOL

 

[Guest]

Hi, im with the previous replys who have said, push down hard on the gas cap while gently turning the key, it works for me!

 

[mikerophone]

Hope for success or at least more soaking tomorrow!

Hope for success or at least more soaking tomorrow!

The only way to get a solvent to the two latches that grip the inside of the filler neck is to take out the sending unit and the petcock ( so said solvents dont ruin either one ) and dump in a bunch and set the tank on its top.

Now what solvent?? Cant be anything that will eat plastic as the bottom cap part of the cap is plastic. I would use 8% vinegar of it was me. Eats the crud and rust but will not harm plastics, rubber, or paint. Dump in half a gallon and set the tank on its top for a few days.

And vinegar is a great soak for the sending unit once its out. Cover it with vinegar and soak over night. Remove the cover and GENTLY clean the contacts with a soft tooth brush and Qtips.

EDIT...if youre gonna replace the cap..which is probably a good idea seeing the seals are hard to find..then some acetone will eat the plastic inside cap and the entire thing will fall apart in maybe 15 minutes or so. remove rest of cap. Be sure to not get acetone on the paint though..

Thanks Chuck, I hope I can just go the vinegar route, and not have to go to the acetone extent!

I 've used from tumbling in the dryer wrapped in blankets ( no the wife was NOT HOME), to nails and gravel with solvent etc etc.

Thanks Tom, BTDT! (Been There Done That) Just don't tell the wife, but she somehow found out anyway, now I just take it to the laundromat, people give a few funny looks when it's banging around and the scraping sounds of the bolts, screws and/or ball bearings inside.

Hi, im with the previous replys who have said, push down hard on the gas cap while gently turning the key, it works for me!

Thanks Chromedome, this tank hasn't been opened in 23 years, pushing down works great on less "aged" tanks that have been opened in at least the last decade. Both of my older 750 (project bikes) tanks came with old gas in them, but they had been registered/run in the last 7 years and opened with the standard amount of pushing down and turning of the key. This key won't turn more than 45 degrees, it needs to turn 90 (1/4 turn) to disengage the spring loaded tangs.

 

[mikerophone]

Didn't get the chance to upload these pics yet, been busy, but I got it open. Vinegar, tapping and more tapping, lube in the key slot and a couple of days soaking and more tapping wiggling and soaking and it started to budge.

Here's what the inside of the cap looked like when I finally got it off, not as bad as Frank Z's above but it was gummed up pretty good:

The inside of the tank was nasty with no visible metal surface and smells like 23 year old turpentine, but I only got about a quart of think nasty aged gas out:



Sending unit nastiness:




Petcock full of dried up sludge and rust particles:



Ed (Nessism) recently posted about his HF soda blaster so I picked one up, along with a 50lb bag of soda - on the bike! Good thing I had a bungee under the seat!!! Before blasting:


And after:


Bought a couple of gallons of unleaded and sloshed, filtered crud out through a funnel with gauze stuffed in it, re-sloshed, re-filtered, filled with nuts, bolts, screws and a chain and shook, drained, filtered, and shook till I got a nice upper body workout for a few hours - tank is too big to fit in the dryer at home and didn't feel like running to the laundromat, the weather was nice outside. Here's a shot of the crud that came out after repeated rinsing and filtering the brown, nasty gas, I ended up with about a half gallon of rust particles powder:



After that I rinsed, dried and filled with almost 4 gallons of vinegar and am already seeing the rust particles floating away, metal looks smooth and nice underneath, appears to be only surface rust, I'll post more pics this weekend of how that turns out.

Only problem I had was that I tore one of the seams of the plastic filter mesh on the petcock, wondering if anyone has ever successfully repaired that - maybe some fuel safe glue or epoxy right along the seam where it meets the filter body will reconnect it...

More recovery pics to come - thanks to everyone's suggestions I was able to crack this nasty tank!