Petcocks (new or rebuild)

Ok gang time to chime in.

1979 kz650B3 the stock petcock is juicy but not leaking....yet!

I have the tank off now for other work being done. Should I rebuild the existing petcock or get a shiney new trick aftermarket replacement? If the latter then which one, bear in mind I am not interested in modifing the tank in anyway.

Thanks,

~R

Is it vaccuum type or gravity fed?

Vaccuum

Rebuilding vaccuum petcocks seem to have a 50/50 chance of working. One of the bikes I have used a vaccuum petcock, it leaked, I rebuild it, still leaked.

Jeff at z1enterprises has the new trick aftermarket stuff. You can go expensive with a pingle, or he also has a cheaper brand that I'm sure works just as well.

You said you don't want to modify the tank in anyway so, you'll have to read up on it on his site. I
believe with one of the new petcocks you must enlarge the hole by filing it down a little.

YMMV.

Post edited by: mariozappa, at: 2007/07/11 14:22

I rebuilt the (vacuum) petcock on my '82 550C3 with the kit from Z1. All I can say is this... it leaked quite a bit at first until I took it back apart and put things back together differently, since I had apparently reassembled it wrong. I didn't have much in the way of drawings or pics to work with (Clymer and parts manual didn't show the orientation of one of the pieces that was critical), which of course led to my incorrect installtion. If you do the rebuild, take lots of pictures with a digicam if you have one -- probably one pic for everything you take apart. My problem was a plastic insert on the vacuum side... there is a tiny vent hole at the top, but the plastic part can be installed upside down and still appear to fit perfectly. You can imagine what happens when you install a part with a vent hole facing down instead of up. Drip, drip...

mariozappa wrote:

You said you don't want to modify the tank in anyway so, you'll have to read up on it on his site. I
believe with one of the new petcocks you must enlarge the hole by filing it down a little.

Depends.

If you have the bolt-on type with 44mm spacing between the bolts, you could get the Suzuki vacuum petcocks that Z1E sells. I did this on my KZ1000, and didn't need to do any mods to my tank. Just had to get creative with the hose routing, that's all. You can read all about it in this thread:

Suzuki Petcock

Post edited by: Skyman, at: 2007/07/11 15:18

Z1 is where I've been shopping. Lordy, Lord you should see my shopping cart.

I will take a peek at the Suzuki thread and see what all that entails. But I really dig rebuilding stuff so I will take all this sage advice crawl back to the garage and see what I come up with.

Thanks to all. I'll post a final solution when I get there.

If anyone's interested here's the beginning of the project to view.

kzrider.com/component/option,com_joomlab.../id,154764/catid,11/

~R

That's a real nice looking 650 you have there. I'd stay stock and just replace the diaphram if that's what's leaking or the oring around the lever or oring between the tank and petcock. It's an easy job and mine have never leaked.