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Discussion Starter #1
I did the acid wash today to get rid of the rust in the tank, and used the rebuild kit to stop the petcock from leaking. I followed the YouTube video I found on how to salvage the old petcock without a rebuild kit as a reference. Now it will stream gas out of the fuel ports in reserve and prime. It will leak out of those ports and the vacuum line if I tilt the tank. I thought I had assembled it wrong, but after pulling it apart three times, it does the same thing. Is this normal?


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No, something wrong, vac port should always be dry.

Wet vac port causes rich mixture and gas in the oil.

Still has a spring in it?
 

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Discussion Starter #3
It does have the spring in it. I pulled the old gasket/diaphragm out and replaced it with the new one from the kit. I thought maybe I put it on the thick plastic piece backwards, but the two nipples that are across from each other matched up with the petcock assembly, and the two diagonal nipples went towards the selector. The selector is pretty stiff (I did try to spray paint it black), and I replaced the gasket on that. I then used the metal compression ring around the selector, but under the cover. I believe that’s how it was supposed to be assembled. What about fuel coming out of the fuel ports on reserve and prime?


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Prime - fuel flows all the time, even with the engine off

Reserve - fuel only flows with engine running, or vacuum applied

I've found that sometimes you have to leave the retainer screws just snug. If you tighten them up all the way, the lever is too stiff.

It's been a while since I rebuilt mine, and I've only done it once. Maybe check a diagram. It doesn't sound like it's switching ports, just free-flowing straight through. The vac port should always be isolated from the gas.
 

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Discussion Starter #5
I just reverified, it is not coming from the vacuum, but it is from both nipples.



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Maybe it's been modified? I recall someone doing that. Drilled it out to eliminate the need for vacuum.

The only settings are on, prime, and reserve, correct? Been a while since I saw one of these.
 

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Discussion Starter #7
Thank you for your help. Reserve, prime and on are the settings. I just don’t want to be dumping fuel, if I ever get this thing up and running, or flooding the carbs with gas.


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Thank you for your help. Reserve, prime and on are the settings. I just don’t want to be dumping fuel, if I ever get this thing up and running, or flooding the carbs with gas.


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Assuming it's assembled correctly, sounds like you need another petcock.

It would be fine the way it is, unless a float happens to stick open some time.
 

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Discussion Starter #9 (Edited)
I took it 5 blocks to get gas... and 3 to lose it all https://vimeo.com/344230920
Tomorrow I will reassemble the petcock step by step and see what I missed. It was on on, but was just pouring out. Any advice would be appreciated

https://vimeo.com/344234076
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Discussion Starter #10
Assuming it's assembled correctly, sounds like you need another petcock.

It would be fine the way it is, unless a float happens to stick open some time.
Please forgive my ignorance, but how does a petcock assembly go bad? Isn't it just an aluminum body? I didn't find any videos that showed exactly how it was reassembled, because i took it apart before my rebuild kit arrived. The back side of the diaphragm was definitely misshapen though.
 

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Please forgive my ignorance, but how does a petcock assembly go bad? Isn't it just an aluminum body? I didn't find any videos that showed exactly how it was reassembled, because i took it apart before my rebuild kit arrived. The back side of the diaphragm was definitely misshapen though.
The diaphragm just wears out, or can stick with enough corn syrup in it.

Will have to go out and look at mine, but I don't think the vacuum port is pointing straight down, not sure if it makes any difference. It is pointing down in this diagram.

If it didn't leak before, I'd say it must be assembled wrong. O-ring in place and all that?

 

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Neither my '02 and '97 have a PRIME position. It is ON OFF RESERVE. I searched several online parts places and many of the petcock internal parts are no longer available. The complete petcock (which was ridiculously expensive) is not available. Even the elongated O ring between the petcock and tank is not available. I believe the petcock from a Yamaha TW200 will fit with some slight modification. These bikes are reaching the age where parts are going to get harder and harder to find.
 

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Prime setting is on earlier model Kawis, 1980s up to some time in early 90s, LTD, Vulcan, etc. Ebay has rebuilt kits.
 

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Discussion Starter #14 (Edited)
It did have a steady leak before, which is why I bought the rebuild kit. But nothing like the downpour from last night. I pushed the bike 5 blocks up hill to get it home. The o-ring that I circled - 670, I do not remember installing or seeing. The kit included a very large o-ring (51039), but I assumed that was for the o-ring at the top of the petcock, next to the tank. I did put in the diaphragm, trying both ways but seeing the nipples it will only go on one way. I had to bunch it up, and pass half of it through the circle in the plastic square. I was afraid I would rip it, but it seemed okay. I will take photos tonight.
 

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Discussion Starter #15
I believe my rebuild kit included that o-ring. Mine seemed fine, so I did not swap it out... unless that o-ring was for between the diaphragm and and the housing. I watched the video on how to fix a petcock without rebuilding, and his did NOT have a gasket there (I know... different bike, but looked like an identical set up). It is sitting on my parts bench right now.
 

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That video is on a Yamaha, isn't it?

If that o-ring is missing, there's the leak. Don't think my kit came with it either. If I recall, the kit was three pieces.

Think that larger o-ring goes on the back of the selector.
 

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Discussion Starter #17 (Edited)
That video is on a Yamaha, isn't it?

If that o-ring is missing, there's the leak. Don't think my kit came with it either. If I recall, the kit was three pieces.

Think that larger o-ring goes on the back of the selector.
This is the video I followed. I am in my office, so I do not want to have the volume on. It is a Kawaski... intruder? My kit had a very large o-ring that looked about the size of the top of the petcock. It had 92055 behind the selector, and the diaphragm with a small o-ring on the back side. I will take a photo of it when I go home for lunch. I didn't see one when I originally pulled mine apart. In fact, my interior looked identical to this (with two ports instead of one)
 

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First vid is a Yamaha Virago.

Now I'm pretty sure there was an o-ring already installed on the diaphragm piston.

At 2:07 in the vid 2, you can see the o-ring on the selector. But I think if it was missing, the selector would be real easy to turn.
 

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Discussion Starter #20
First vid is a Yamaha Virago.

Now I'm pretty sure there was an o-ring already installed on the diaphragm piston.

At 2:07 in the vid 2, you can see the o-ring on the selector. But I think if it was missing, the selector would be real easy to turn.
I believe we are talking about two different o-rings. I installed the new 92055, that is behind the selector (fits in the grove on the back side) that came with the kit. It was the 607 o-ring that I do NOT have, nor did I see it when I disassembled the petcock. Unless we are talking about the same thing. The 607 looks like it is on the back side of the housing, facing the engine. Please correct me if I am wrong. I love teachable moments.
 
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