[Paulsblocks]

I have a 1986 Kawasaki Vulcan 700. I was recently digging through the petcock (because I'm an idiot and was trying to fix something that wasn't broken) and lost the spring. I replaced the spring with one from an old petcock of an 81 Suzuki gs450. now I've put the petcock back together and when I put a vacuum on the petcock (by sucking on the hose fuel won't flow. if I turn on the prime setting it will. I was originally just gonna buy a new petcock, but they're around 100$ for the one I need, and I don't really wanna spend that money yet because I've only had this bike for about a month, and idk if I wanna put that much money in it.. Will it cause any problems if I just run the bike on prime all the time? also does anyone know anywhere that might have the petcock i need for cheap? I was thinking about buying a rebuild kit, but the diaphragm isn't torn so I'm not sure that's the problem, and it holds a vacuum just fine.

This is the Petcock I need. when i look for cheaper Chinese built ones they aren't even remotely what i need as they only have 1 fuel outlet

 

[Retired Guy]

I don't think it will hurt anything to run it on the Prime position, just be sure to shut it off when you park it. Just my opinion.

 

[Paulsblocks]

Alright, that's what I was thinking. I just wasn't sure if the needle valve will be able to regulate the fuel flow

 

[bpe]

I just wasn't sure if the needle valve will be able to regulate the fuel flow

If the float needles are seating properly it should regulate the fuel flow, if not then they won't. The rebuild kits for those Kawi petcocks are ****. If all you need is a spring, you may be able to find a used one on ebay. To take the spring out of and use in the known to be good petcock.

 

[Paulsblocks]

If the float needles are seating properly it should regulate the fuel flow, if not then they won't. The rebuild kits for those Kawi petcocks are ****. If all you need is a spring, you may be able to find a used one on ebay. To take the spring out of and use in the known to be good petcock.

alright, thanks for the advice. I found a used petcock on eBay so I might buy that and see if it works

 

[Unkle Krusty]

Fuel is supposed to flow on prime. Good be the spring you used is too strong, so the vacuum can not open it. Modify or change the spring, or find the old one.
I can not find my medium size whacking stick. It has an easy to spot yellow handle. It will make its presence known to me some day.

UK

 

[Paulsblocks]

Fuel is supposed to flow on prime. Good be the spring you used is too strong, so the vacuum can not open it. Modify or change the spring, or find the old one.
I can not find my medium size whacking stick. It has an easy to spot yellow handle. It will make its presence known to me some day.

UK

I was thinking I might have to modify the spring, but i couldn't even get it to flow by sucking on it (that's what she said) and if I'm applying that much vaccum i wouldnt thing the spring is what's wrong

 

[bpe]

(that's what she said)

and if I'm applying that much vaccum i wouldnt thing the spring is what's wrong

But if that's the only variable that changed from when it worked, that would be the place to look.
Could you have possibly assembled it wrong?
Is there a rubber channel wheel that could have gone in wrong. (mine is a little different than yours)

 

[Paulsblocks]

The petcock is pretty simple and I never took out the channel wheel so I dont think it could've gone bad. Or be put in wrong. Also I really dont think the spring was powerful enough to withstand the force of a human vacuum