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Discussion Starter · #1 ·
I have taken the vacuum petcock of my 81' Deluxe apart. After I realized that the brand new,non vacuum petcock I had laying in my garage did not fit 81's tank, I decided to go with a rebuild kit. First of all...I don't like these vacuum petcocks too much. Too many parts for a fuel valve!! Also, I am looking at the rebuild kits, and they don't even have all the parts I need(I have drilled into those rivets that hold the manual valve to get to the rubber seal behind it).



So, my question is: are there other aftermarket petcocks with the same flow rate(maybe not that relevant)that will fit onto the tank without modifications?

The rebuild kits are not that cheap either. I would rather pay a little more and save myself some headache. Honda has discontinued to sell the OEM ones.





Any suggestions?



The little round screen you see in the picture needs to be replaced. It is falling apart. No screening going on here anymore, plus, debris from it can plug things up!

 

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Discussion Starter · #3 ·
What about putting it back together and bypassing it?



Click here,



http://globalcxglvtwins.hostingdelivered.com/viewtopic.php?f=19&t=290



Shep, why rebuilding and then bypassing it. Also, I just think in these vacuum petcocks there are too many parts that can cause leakage. i will rebuild it though, if I don't find an alternative. An then, I might as well hook it up and let it do its vacuum thing.

Or are you suggesting putting it together with the old parts? Won't it leak again?
 

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Shep, why rebuilding and then bypassing it. Also, I just think in these vacuum petcocks there are too many parts that can cause leakage. i will rebuild it though, if I don't find an alternative. An then, I might as well hook it up and let it do its vacuum thing.

Or are you suggesting putting it together with the old parts? Won't it leak again?


Yes I was suggesting you use the old parts but if they are going to leak then it's a no no




You say you can't find a normal petcock to work?



I'm sure I remember someone on here fitting a cheap universal one.You just need to get the thread size as there were are two sizes depending on the model.
 

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Discussion Starter · #5 ·
Yes I was suggesting you use the old parts but if they are going to leak then it's a no no




You say you can't find a normal petcock to work?



I'm sure I remember someone on here fitting a cheap universal one.You just need to get the thread size as there were are two sizes depending on the model.


The 81'Deluxe is the one with the bigger thread. I think it is a 18mm. The 80' Deluxe has a smaller thread, probably 16mm.

I was just wondering, if I have to worry about the flow rate,when I look for a universal petcock? The petcock of my 80' Deluxe also has a smaller diameter nozzle at the petcock and at the carb.



Has anybody in this forum any experience with substituting petcocks from other bikes that will fit on my 81 Deluxe?
 

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I also did not like the vacuum petcock. The 80 and the 81 bikes (cx500c) use the same carbs. They were used on many honda bikes. I liked the 81 petcock since it has the larger pipe, barb, and hose on it.

In your picture you show a spring. That spring holds the shut off diaphram closed. I moved that spring to the other diaphram To make the petcock normally open. I then cap off the vacuum fitting on the right carb. Also the vacumm fitting on the petcock. Much easier on the start up and the starter.

I have had it that way for two years.
 

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I got a manual petcock for my Suzuki GS1100L from Z1 Enterprises. I got rid of the bike (traded it for my Silverwing
) before I got it installed and working right. They have a couple of different kinds of petcocks, and adapter plates you can buy to let a generic petcock screw into it.
 

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Discussion Starter · #10 ·
Edit: double post


Okay, I have been staring at this petcock for too long. I am just going to seal it back up without putting the vacuum seals back in. I will just seal the whole thing, solder the two openings shut(a fuel line will just leak sooner or later)....and I will have my manual fuel valve with the least chance of further leakages. I will take pictures.



Here is a 18mm and 2½" long petcock I found. They sell them for 32 bucks plus shipping on ebay. I have sealed my stock vacuum petcock without putting the diaphragms in. If I start seeing any leaks with this on, I will buy a new petcock.





My link
 
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