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Discussion Starter · #1 ·
I guess it may have been naive of me to think the the original wouldn't leak after sitting idle since 1988. Well I thought why not try...it was ok on reserve, but leaked in the 'ON' position. This is just the standard Petcock for a 79CX500C, so no vaccum diaphram to worry about which is nice. I picked up the infamous 4 way O-ring at the honda dealer for 3.50, but found that the gasket and intank tube run 28 bucks.



Does anyone have a pic of the gasket that seals the tank connection to the petcock?



I am guessing from a couple of google image searches that it is just a simple ID/OD washer with some thickness. I have some rubber material and would like to have a crack at making this gasket. I will post pics of the rebuild if it proves to be successful. I know I can 'bay' a whole new petcock for about 18 bucks, but again its the thrill of salvaging that I like...and if it works, it will have ony cost me 7 bucks, and others can benefit if they want to take the time!
 

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I used an oring. Cant remember which size though. You might want to hit up a place like harbor freight that has a nitrelle random box of rings that you can try and find the right one.
 

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or just take the petcock to your local hardware store and go through what they have in their drawers in the plumbing section. The ACE Hardware near me must have 500 different ones.
 

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Discussion Starter · #4 ·
well I finished my rebuild, and though the Petcock Seal I purchased works, it is a bit tight, and slightly thicker than the stock one. I did notice that the newly purchased one has a '5' and a '1' on it and corresponds to part number 16955-268-020.



The original has a '4' and a '2' on it--would anyone happen to know what Honda Part Number this one corresponds to?



 

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Discussion Starter · #5 ·
Here are some of the other things I tried.



The Oring I used for the tank seal is an old fuel injector Oring from a Chevy Malibu. I reinforced the ID with an old piece of fuel line with a flared end--this way when I tighten down the petcock nut, the Oring has something to push against towards the ID and 'crush' giving me a solid seal. No leaks to date. The metal fuel line also prevents the Oring seal from obstructing the reserve line port.







I know I asked earlier, but my previous posted pic of the petcock seal, note the '5' & '1' on the new seal--the old one has a '4' & '2' on it...I would really like to have "THAT" part number!
 

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I know I asked earlier, but my previous posted pic of the petcock seal, note the '5' & '1' on the new seal--the old one has a '4' & '2' on it...I would really like to have "THAT" part number!
That isn't going to be a part #, it's probably a unique manufacturing date code that would have no meaning except to them.
 

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Discussion Starter · #7 ·
That isn't going to be a part #, it's probably a unique manufacturing date code that would have no meaning except to them.


Thanks Marshall, I understand that those two won't be a part number. I did find that the one I have used with the 5 & 1, corresponds to that 16955-268-020. I was wondering if anyone had a different Honda part number for the petcock seal, one that might be closer to the original, and be marked with a 4 & 2 on it. Maybe like you have indicated it is a random number system that tells honda what batch & lot or something like that...I just don't know, but can say that the petcock valve is a bit tight...maybe it just needs a little time for the seal to relax a bit.
 

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I used teflon faucet packing. Has not leaked so far. Sick of trying to find those elusive metric o-rings.
 

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Honda wouldn't be making them, it would be an outsourced part. These were only made in two sizes that I'm aware of and the difference may only be for vacuum or non-vacuum models.
 

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Discussion Starter · #10 ·
Honda wouldn't be making them, it would be an outsourced part. These were only made in two sizes that I'm aware of and the difference may only be for vacuum or non-vacuum models.


Would you happen to have the two Honda part numbers? I am thinking the one that I have may be for the vacuum model, and my 79CX500C is a non vacuum style...
 

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Sure don't, but if you know the year they changed over you might be able to look them up somehow, the thing is I thought Honda only sold complete petcocks since they were riveted together.



The two sizes I'm aware of were two distinctively different diameters. You might try going to eBay and searching through GeorgeFix's store, or just searching eBay>Motors>Motorcycles>Parts and Accessories for Honda petcock as they'll show up that way inbetween the entire units.
 

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So to rebuild a petcock would need to drill out the rivets then tap threads?
 

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Discussion Starter · #13 ·
So to rebuild a petcock would need to drill out the rivets then tap threads?


Before you grind off/file off the top part of the rolled over posts that look like rivits, I would pre drill your tap-drill holes using the dimples as pilots.



They aren't really rivits so-to-speak...originally they were posts coming from the cast body of the petcock, and then rolled over/pressed/stamped to keep the top plate on...Once you have your tap drill holes completed, THEN I would file/lightly grind off just the tops of them JUST so you are able to remove the top plate that keeps everything in there. Remove the plate and you will see what I mean. Those posts will help you realign that plate when you go to put everything back together.



Not sure if your petcock is a vaccum type or not...never rebuilt one of those, mine is just a standard gravity type.



Keep us posted on your progress. When you are done the handle will feel stiff, but with time will loosen up a bit. I was concerned at first, but here I am months later and no leaks, and she is still performing NICELY
 

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K, thanks
 

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'84 CX650E that is evolving into a GL500
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- Does anyone know if this part will this fit a vacuum petcock?



I am using a GL1000/1100 seal from Randakk in mine. It appeared to be much too small when installed, but when I removed it a year later to install a Suzuki seal that was the correct OD and almost the right small hole centres it had swollen up to the right size. The Suz. part didn't seal well so I ne4ded up putting the 1000/1100 seal back in and it seems to work OK. I am not sure whether the seal swelling is caused by the E10 that is just about universal in the fuel here.



- What did you do for the seal around the perimeter of the petcock handle? I am using an o-ring from the assortment I got from Princess Auto (similar to Harbor Freight but in Canada) but it the original has a square cross section and the O ring makes it very stiff. Every year or two I have to take it apart and apply a bit of silicone grease to lube the o-ring.



- Re the bit of fuel line in the petcock/tank o-ring: I have been using plain o-rings for years with no leaks at that point. I guess it won't hurt but it isn't really necessary.



Re the numbers on the seals: I think they are probably just the mould & cavity numbers (eg. mould #5 cavity #1 or vise versa). On examination of several old vacuum petcock seals (no I don't throw anything away
) I found one 7-9, one 2-1 and one with a readable 2 but the other number worn off (this seal is very badly damaged). These numbers are probably used for quality control purposes (if you start finding one number out of spec its time to check the mould).



BTW: I found some #6 screws that have a little slot (looks like a fine hacksaw cut) lengthwise on one side of the threads and about half way across the end so that they will cut their own threads in soft metals so I didn't need to use a tap when I did my bikes' petcocks. You might be able to modify regular screws this way with a Dremel or a razor saw if you are very careful.



Re drilling for the screws before you remove the staked over posts: This is very very good advice. I have a petcock that I ruined before I figured this out.
 
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