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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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Discussion Starter · #1 ·
The petcock on my GL650 is weeping around the lever. What's the current wisdom regarding this? Should I rebuild it, or replace it?
I'm fine with the vacuum function, so I'm not interested in deleting that.
Thanks in advance for experienced input.
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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Discussion Starter · #2 ·
All of the replacement vacuum petcocks I find on eBay appear to lack the vent nipple. Suspicious of the quality of the replacements, I'm leaning toward rebuilding.
I see two similar rebuild kits from Darkhorse Motors on eBay. This one is from Japan at $24.30.
This one is from Taiwan at 16.47,
Does anyone have experience with either of these to justify the cost difference?
 

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I don't think that those kits will cure the leak around the lever if the leak is due to the wafer with the four holes which is mostly unobtainable.
 

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I have tried to rebuild about 4 of those and yes it is the worn out 4-hole rubber wafer.
You need to drill out the rivets and after (maybe ) fixing the wafer by either flipping it over and/or filling the worn rubber cracks with gasket cement and/or making a new rubber 4-holer yourself and/or some other Rube Goldberg fix, you then need to replace the rivets with 3mm tapped allen head screws.
It's a very real hit or miss operation.
I win about 50% of the time.
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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Discussion Starter · #5 ·

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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Discussion Starter · #6 ·

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'84 CX650E that is evolving into a GL500
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The kits only include the parts for the vacuum valve. The main valve has the wafer that forms part of the valve itself and an X-ring that seals the lever's plate. If fuel is leaking around the lever it has to be getting past the X-ring. You might be able to fix it temporarily by drilling out the stakes that hold the outer plate on, drilling & tapping them for small bolts, flipping the wafer over and replacing the X-ring (when I did this I used an O-ring - it was harder to turn the lever but it held until the wafer caused problems again).
But I would only consider that a temporary measure because at almost 40 years old I wouldn't trust it to last.

Some years ago a bunch of us did a bunch of testing with various wafers made for other petcocks. None of the ones we could find were the right size for the vacuum petcock; A few sealed initially when stretched to fit but none lasted for very long.

After wasting way too much time on trying to get the original one to work dependably I gave up and bought one of the non-vac ones from Bay.
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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Discussion Starter · #10 ·
Thanks. I found the same one on eBay for about 2/3 the price. I imagine they come from the same source.
I assume you reversed the diaphragm plate so the vacuum nipple points under the tank.
 

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Measure and post the dimensions on the inner 'wafer' (I think of it as a gasket, some may call it a seal, as in valve seal). There are rebuild kits available that might include what you need... a Goldwing supplier (Randakk.com) made viton seals for later 'unrebuildable' petcocks, perhaps one will work for you. I probably have 6-8 diff petcock seals I can compare it to... maybe we can find a fix.

I have rebuilt a number of riveted petcocks... drill out rivets with smallest drill bit possible, tap hole with 3mm tap then use appropriate pan head screws (3mmX7mmX0.5 is what I use) to reattach outer plate/wavy spring/lever. The alloy used in petcocks is easy to tap, just go slow and back out/clean tap often.

It's nice not to have to think about the petcock when the ride is over... but it's VERY NICE not to foul carbs because you continue to feed gas in while sitting still. Had one customer that put a label on his tank "TURN THE GAS OFF, STUPID" after spending $400 to clean/rebuild carbs
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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Discussion Starter · #12 ·
My replacement should arrive Saturday. Then I can disassemble the original and do some measuring.
 

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1982 GL500i
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I got 4-hole petcock seals from Randaak 5 years ago to fit my 81 Goldwing, and my 82 Silverwing. i can't find the empty packages to tell you the part #s I used, but he still has a variety. It helps to take your petcock apart so you know the diameter of your existing 4-hole seal.
 
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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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Discussion Starter · #14 ·
... drill out rivets with smallest drill bit possible, tap hole with 3mm tap then use appropriate pan head screws (3mmX7mmX0.5 is what I use) to reattach outer plate/wavy spring/lever.
3mm pan heads are used inside desktop PCs. I have a bunch of them. And I have a 3mm tap from doing the ground mod in the starter.
 
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'84 CX650E that is evolving into a GL500
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AFAIK, Randakk never produced a wafer to fit the GL500 petcock. H did have dies made to produc the ones for the GL1000/1100, CBX and maybe a couple more but none of them are the right size to fit the vacuum petcocks.
I had one of his GL1000 wafers in my vacuum petcock for a while. It seemed promising at first but eventually I tried something else that almost fit.
BTW: Randall "Randakk" Washington retired a few years ago and sold out to Dime City so who knows what they are selling under his name now.
 

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AFAIK, Randakk never produced a wafer to fit the GL500 petcock. H did have dies made to produc the ones for the GL1000/1100, CBX and maybe a couple more but none of them are the right size to fit the vacuum petcocks.
I had one of his GL1000 wafers in my vacuum petcock for a while. It seemed promising at first but eventually I tried something else that almost fit.
BTW: Randall "Randakk" Washington retired a few years ago and sold out to Dime City so who knows what they are selling under his name now.
Thanks for the news flash, Bob.

BTW, I did post a link to the petcock parts page of the site as it currently stands. So the answer to your question "who knows?" is simple, anyone who takes the time to go and look for themselves.

P.S.
I've never been to the moon, myself, but I'm not going to doubt someone else did, just because I couldn't go. Even if someone else's efforts don't live up to your expectations, at least they made the effort.
 

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'84 CX650E that is evolving into a GL500
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I'm not the only one on this forum that gave up in finding a suitable wafer after several tries. I was one of the last of the group that were trying to find one to give up. Randall W & I emailed back & forth about the subject a few times and he even sent me the GL1000/1100 wafer to experiment with.
I looked at the page you linked before I posted. Several items are obviously the ones he was having made, some of the stuff is not and some I'm not sure about. As I said, who knows? I wouldn't trust the generic stuff from unknown sources they sell, though.
 

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You keep saying "who knows" as if no one does, or can. This is one of the few "support" groups where I have had more than one person tell me that the things I have accomplished are just not possible, primarily because they, themselves, have not been successful with whatever the subject may be. I tell you what, Bob, so I don't further embarrass you or the one or two other primadonnas who do this, I will keep my discoveries to myself, and you can continue to tell others that if you can't do it, no one can. Cheers!
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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Discussion Starter · #19 ·
I got 4-hole petcock seals from Randaak 5 years ago to fit my 81 Goldwing, and my 82 Silverwing.
Do you recall if they were different parts for the Goldwing vs Silverwing petcocks? That would at least help me eliminate a possibility.
 
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