Fuel cock rebuild questions

[Asmodeous]

I finally got my carbs rebuilt except I'm missing 1 of the springs, which I've ordered. When I was inspecting the rest of the parts that I'd taken off the bike I noticed the pain on the gas tank by the petcock was bubbling/flaking. I investigated and found that the petcock was frozen/gummed up with old fuel.

I took the it off the tank and got it disassembled with some carb cleaner. The gasket was toast and I pulled the rest of it apart to check it thoroughly. I noticed two things wrong on the inside. The o-ring for the control valve is toast, can I get a new one of these ? It doesn't seem to be listed in any parts catalogs I've seen. Is that little funky spring on the inside necessary for the thing to function ? Mine was bent and I'm not sure it will work properly.

Ok, did a little research using the search button and found that rebuild kits are offered. I got one of ebay for 20 bux shipped.

Anyone know about that internal spring ?

[2wheelnPit]

the springs there for a reason ...

[Asmodeous]

I know its there for a reason but I think the only reason it is there is to provide resistance for when you turn the petcock. I am just wondering if it will actually effect the operation of the petcock in terms of flow if it isn't there.

[Kreylyn]

I know its there for a reason but I think the only reason it is there is to provide resistance for when you turn the petcock. I am just wondering if it will actually effect the operation of the petcock in terms of flow if it isn't there.

It is needed to keep pressure on the inside so that the external clips don't turn loose, releasing the entire assembly.

A new one comes in the rebuild kit you purchased.

Check here... first pic shows all items included.

http://katriders.com/vb/showthread.php?t=96553

Krey

[Asmodeous]

This is funny to me because I knew I should have mentioned which spring I was talking about. Thats not the one I was inquiring about. The one I was wondering about is the one that sits behind the white plastic piece. Its not your traditional looking spring. I think its function is to provide rotational tension for the petcock. I'm not really sure if it does anything else ?

[Kreylyn]

This is funny to me because I knew I should have mentioned which spring I was talking about. Thats not the one I was inquiring about. The one I was wondering about is the one that sits behind the white plastic piece. Its not your traditional looking spring. I think its function is to provide rotational tension for the petcock. I'm not really sure if it does anything else ?

Um, there are only 2 springs...

The small one behind the selection knob. I described what it does.

The large one behind the diaphram assembly. This one is what puts pressure on the diaphram to seal off the flow of gas. Vacuum is applied when the bike is running to counter the spring and open it so fuel will flow.

If that spring is not there or not working properly... fuel will always flow.

Let me check if I have a spare...

Krey

[Asmodeous]

I think that spring for the diaphragm is the one that is messed up. It doesn't look like a regular coiled spring right ? When I took the petcock apart that spring was noticeably bent out of shape. Let me know if you have a good spare you are willing to part with.

[Kreylyn]

I think that spring for the diaphragm is the one that is messed up. It doesn't look like a regular coiled spring right ? When I took the petcock apart that spring was noticeably bent out of shape. Let me know if you have a good spare you are willing to part with.

If this spring, this is how it should look...



I just checked. I do not have a spare atm. A good source though would be to take yours to an appliance parts place to see if they can match one up that will work.

Krey

[Asmodeous]

Ok, thats not the spring either. It doesn't look like a regular spring. If you flip that petcock over and take apart the valve you will see a spring behind the white cone piece on the inside. You can see the back side of it if you take that diaphragm off completely.

[Kreylyn]

Ok, thats not the spring either. It doesn't look like a regular spring. If you flip that petcock over and take apart the valve you will see a spring behind the white cone piece on the inside. You can see the back side of it if you take that diaphragm off completely.

Ah, got ya...

That is the selector spring for the petcock... it pushes the diaphram open when you set it to prime so that fuel flows.

It's supposed to be bent, with the tip of it pointing directly center of the hole where on the other side... the diaphram sits to push it out.



Krey

[Asmodeous]

Doh, mine looked bent like it didn't come out of the spring making machine that way. I guess its fine then. I'll reassemble it when I get the kit.

Thanks !

[Evil Jebus]

thanks once again for an awesome tutt on pet cock you are a legend

[SlipKid]

Okay, I have a question... Which way is that white plastic plate supposed to face? Flat side towards the diaphragm spring, or towards the fuel stopper side? I should have paid more attention taking it apart, but then again, I can't be sure it was in there correctly in the first place...

My guess is the flat side goes towards the stopper side...