Gas Tank Cap / Latch Corrosion, Cleaning, and Modification

[TallyRex]

FWIW - I've got SSR keyless gas caps on both the C-14 and my ZRX and have never had a venting problem

[maxtog]

I will report back on the long-term results of the "operation", especially to see how effective using white lithium is.  But although I know it is going to corrode again, it is now pretty easy to fix (and I won't let it get this bad again).

One year followup/update....

I have only had a few other times it energetically "poofed" out air when going to fill it, so I haven't taken action on that issue.   But is already starting to corrode significantly again, and getting harder to open.      Freaking ethanol.

MOB recommends coating parts with lithium grease.  As you know, this is what I did the last time I took it apart and put it back together.  It helps, but doesn't seem to last very long.  I might be doomed to this being an annual "take apart, clean, and lube" type thing.

Rick recommends coating parts with aviation lube ( http://www.aircraftspruce.com/catalog/cspages/ezturnlube.php )

[Conrad]

I was getting the occasional bit of corrosion around the key hole of the gas hole till I slopped on a bunch of Lock Ease. I worked the key in the lock and got the liquid spread around pretty well. After it dried it left a film and it seems that this film has prevented any more corrosion from forming. Plus the lock is MUCH easier to turn now.

YMMV

[Eupher]

I was getting the occasional bit of corrosion around the key hole of the gas hole till I slopped on a bunch of Lock Ease. I worked the key in the lock and got the liquid spread around pretty well. After it dried it left a film and it seems that this film has prevented any more corrosion from forming. Plus the lock is MUCH easier to turn now.

YMMV

Did you disassemble the latch assembly at all before applying the Lock Ease? It seems that the corrosion also gets inside the assembly, along with the exterior and springs.

I would think maxtog's lithium grease attempted to do the same thing -- put a film on the exposed aluminum inside the assembly. Doesn't seem to work for the long haul, though I would think it's better than nothing.

[Conrad]

Did you disassemble the latch assembly at all before applying the Lock Ease? It seems that the corrosion also gets inside the assembly, along with the exterior and springs.

I would think maxtog's lithium grease attempted to do the same thing -- put a film on the exposed aluminum inside the assembly. Doesn't seem to work for the long haul, though I would think it's better than nothing.

I wanted to try this out without taking anything apart first. It seems to have worked for me. 

[AZ-ZG]

I just work over the latch mechanism with WD-40 when it starts to get fussy. 
Take it as another bit of maintenance.   

Happened in AZ where relative humidity was low and it does it in the swamp of N FL. 

I have actually opened the cap on trips and seen layers of corrosion ready to come off.
Grab a paper towel or sacrifice a micro fiber, cover the tank opening, and start busting that  off with a gloved hand.

Tried to keep a chunk of it to see if it broke down in gasoline but lost it.   

If any of that mess has fallen into the tank there have been no issues @ 103,000 miles. 2009 

[maxtog]

Well, it has been almost exactly two years since I started this thread with the last round of aggressive cleaning due to near failure of the latch and lock.  The mechanism has been getting worse the last few months and the last fillup, I almost couldn't get the cap open at all.

Today I took out the latch and it was cleaner than before, no black stuff (which I now think was the graphite), but lots of white powder again (see photo).  I hadn't added ANY type of additional lube the last two years.  I used a Dremel with wire brush to remove it from all surfaces.  This time, I decided to try a different lubricant, a thin amount of molybdenum disulfide grease, it is the only other thing I have left to try.  I applied not only to the wear surfaces, but pretty much all over.

The lock mechanism was just as bad, but I wasn't in the mood to remove it and deal with the hundreds of parts falling everywhere, so I shot some spray graphite into it for now.  Since the lock is still not really clean, it is still a bit stiff (and doesn't spring back), but a lot better than before.

[gPink]

looks like salt corrosion

[maxtog]

looks like salt corrosion

It does, but I don't think there is salt in my gas tank!

[VirginiaJim]

I'd replace it.

[gPink]

The bike?

[B.D.F.]

That is the worst case of corrosion I think I have ever seen on a motorcycle. Seriously. And I cannot imagine why that is happening either. ?? ?? ??

Yep, I would replace that ass'y; by the time you get the corrosion off, I believe the parts will have lost all sizing and toleranceing.

Just curious but is the bike subject to a lot of condensation? I mean do you cover it, for example, and find it wet underneath the covering often?

Are you very close to the ocean?

Whatever is going on there is extreme at the very least.

Brian

Well, it has been almost exactly two years since I started this thread with the last round of aggressive cleaning due to near failure of the latch and lock.  The mechanism has been getting worse the last few months and the last fillup, I almost couldn't get the cap open at all.

Today I took out the latch and it was cleaner than before, no black stuff (which I now think was the graphite), but lots of white powder again (see photo).  I hadn't added ANY type of additional lube the last two years.  I used a Dremel with wire brush to remove it from all surfaces.  This time, I decided to try a different lubricant, a thin amount of molybdenum disulfide grease, it is the only other thing I have left to try.  I applied not only to the wear surfaces, but pretty much all over.

The lock mechanism was just as bad, but I wasn't in the mood to remove it and deal with the hundreds of parts falling everywhere, so I shot some spray graphite into it for now.  Since the lock is still not really clean, it is still a bit stiff (and doesn't spring back), but a lot better than before.

[VirginiaJim]

The bike?

The gas tank cap and latching mechanism or whatever is corroded.

[maxtog]

That is the worst case of corrosion I think I have ever seen on a motorcycle. Seriously. And I cannot imagine why that is happening either. ?? ?? ?? 

It is pretty crazy.  I am not alone, others have reported the same thing, but it doesn't seem to be common, either.

Yep, I would replace that ass'y; by the time you get the corrosion off, I believe the parts will have lost all sizing and toleranceing.

The metal is actually eaten away and pitted.  I do plan to replace it at some point.  I suppose I have to research which parts are available... I would have to at least retain the cylinder for the lock.

Just curious but is the bike subject to a lot of condensation? I mean do you cover it, for example, and find it wet underneath the covering often?

This is not a low humidity area, it is kept covered always, in a tent-like structure with vents.   I don't find it wet, though.

Are you very close to the ocean?

Yes and no.  10 miles from the ocean and 7 from the bay.  I still think it is some type of electrolysis due to dissimilar metal in the presence of humidity, though.  Stupid Ethanol gas attracts water.
 

Whatever is going on there is extreme at the very least.

Agreed.

[jimmymac]

Mine was doing the same thing, so I replaced it. Once it starts, there's no stopping it. I tried to catch it early and used all kinds of lubricant, but the corrosion got worse every day. I've owned plenty of these bikes, and sometimes it just happens.

[B.D.F.]

I am skeptical regarding any coverings of any vehicle, no matter how well vented. That plus the fact that the part of the bike that is corroding into next week being at the top of the bike makes me suspect the cover.

This is nothing more than a passing thought, no observation and certainly no recommendation.

Brian

<snip>

This is not a low humidity area, it is kept covered always, in a tent-like structure with vents.   I don't find it wet, though.

<snip>

[maxtog]

Well, it has been almost exactly two years since I started this thread with the last round of aggressive cleaning due to near failure of the latch and lock.  The mechanism has been getting worse the last few months and the last fillup, I almost couldn't get the cap open at all.

Today I took out the latch and it was cleaner than before, no black stuff (which I now think was the graphite), but lots of white powder again (see photo).  I hadn't added ANY type of additional lube the last two years.  I used a Dremel with wire brush to remove it from all surfaces.  This time, I decided to try a different lubricant, a thin amount of molybdenum disulfide grease, it is the only other thing I have left to try.  I applied not only to the wear surfaces, but pretty much all over.

Well, here I am again, almost couldn't open it at the gas station.  Took it apart and cleaned it.  Molybdenum disulfide wasn't any better than anything else, so I went back to white lithium.  Until next time...

[VirginiaJim]

Living near the ocean, eh?

[Bob Skinner]

How thick is powder coating, and could that work on these parts???

[maxtog]

How thick is powder coating, and could that work on these parts???

I have no idea.  I would think it might cause issues with operation, though.

I wish I could just order a replacement latch part.  I would order a whole thing, but I am worried about the lock and reassembly of all the tiny parts which might not come with instructions (and there is NO diagram or other info in the factory manual).