[JostVice]

Hello guys, i'm in the process of restoring my '93 GPZ500, and my petcock is in very bad state. I bought a replacement one off ebay but it comes with a 6mm fuel line and no vacuum, and i think the quality is not so good. Took a peek inside and i think even the letter for RES and FUEL are reversed, watch out for that!

After reading around in the forum about what the vacuum port does, i am wondering what do i need to do to work without the vacuum port? Do i need to do something in the carburator?

I am considering restoring my old petcock, maybe it could work for the wiki manual.

Also, is there a list of compatible petcocks? I checked the wiki and there is no list. I've found between Kawasaki that supposedly the part number is shared between the EN 500, EN 450 and Vulcan, and in the forum @
Plasmid369 says the Yamaha 5LP-24500-01-00 Raptor petcock works and costs 20$

 

[john z]

The vacuum line comes off the left side of the carb and actuates the stock petcock. Fuel does not flow if no vacuum is present.

You can run an aftermarket petcock that has no vacuum line, but make sure you cap off the vacuum from the carb and ALWAYS turn off the new petcock when not riding.

It is a good idea to turn off the fuel on a stock one too, but forgetting shouldn't empty your tank on to the floor.

John Z.

 

[TMF]

Warning to all. Not sure if my experience is typical but I also installed a cheap EBay non vacuum petcock on a newly acquired 2000 EX500. Ran great on the bench. On the road the bike would stop running or at best limp along. I spent 15 hours or so taking carbs apart, etc. The light came on when draining float bowls on the road and seeing little gasoline come out. After fitting a stock vacuum operated petcock the problem was immediately resolved.

 

[Saabnut]

Here's what I have found with fuel petcocks.
Cheap aftermarket petcocks are just that; cheap. Yes, you can use that garbage aftermarket unit you got, but if you want to do it right the first time, either get an OEM replacement or rebuild the old one. When rebuilding, same aftermarket quality theory applies. I had an ebay special petcock diaphragm fail after just 1,000 miles, then the one I replaced it with failed again after a similar amount of time.

One more quick anecdote on aftermarket petcocks. The one on my old Honda XR600 was leaking, so I got one reasonably priced on ebay. When I pulled it out and compared it to the original, it become obvious quickly it was poorly built and that whoever designed it clearly never actually laid eyes on an OEM part. So, in the trash it went and got a factory unit, been quite pleased with that decision.

 

[JostVice]

Here's what I have found with fuel petcocks.
Cheap aftermarket petcocks are just that; cheap. Yes, you can use that garbage aftermarket unit you got, but if you want to do it right the first time, either get an OEM replacement or rebuild the old one. When rebuilding, same aftermarket quality theory applies. I had an ebay special petcock diaphragm fail after just 1,000 miles, then the one I replaced it with failed again after a similar amount of time.

One more quick anecdote on aftermarket petcocks. The one on my old Honda XR600 was leaking, so I got one reasonably priced on ebay. When I pulled it out and compared it to the original, it become obvious quickly it was poorly built and that whoever designed it clearly never actually laid eyes on an OEM part. So, in the trash it went and got a factory unit, been quite pleased with that decision.

Well you guys are right and my cheap ebay fuel petcock gave away and is now losing fuel.

So do you suggest i search for the original Kawasaki one, or is there any better option? Any shop that sells EU?

 

[ducatiman]

a pretty good go-around on petcock rebuild here Rebuilding/ Resealing/Restoring Petcock

 

[yorkie]

the subject of petcocks can be controversial as opinions differ. one thing is for sure if you buy the cheap ones they will fail pretty quickly, this is because 90% of the stuff on sale cheap is in fact Chinese (copied) stuff. poorly made with inferior materials and design. if you want a precision one they cost a lot. either go stock or pick a good aftermarket one from say Pingel or Seely something like that.
personally I don't like vacuum operated petcocks but prefer the manual type reason well there is more components to go wrong (and they do) also they make you lazy, the fuel is cut off when the engine stops so no need to turn it off manually is there right, no wrong because one day you will park the bike up, come back it to find out all the fuel in the tank is now in the crankcase, (been there done that) "got the T shirt".
a manual one forces you to turn it off every time you park the bike then the scenario can never happen, of course this is only my opinion others may see it differently. but in over 60 years of riding bikes never came across of a flooded crankcase until the auto (vac) petcocks came along. go figure.

 

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a manual one forces you to turn it off every time you park the bike then the scenario can never happen, of course this is only my opinion others may see it differently. but in over 60 years of riding bikes never came across of a flooded crankcase until the auto (vac) petcocks came along. go figure.

Same experience here, yorkie. Never had a flooded crankcase until I got a bike equipped with a vacuum petcock that the engineers thought would prevent flooded crankcases.

For me, that particular problem is gone forever now that I've moved on to a fuel injected bike. The only way that new bike's crankcase will flood is if there is some sort of electrical fault that turns on the fuel pump while at the same time an injector is stuck open. Not likely. The new bike doesn't even have a petcock but if it did I'd probably still turn it off anyway just out of habit.