many things needed as far as tuning on a KZ550A1.

Sometimes petcock issue may be resolved by: remove from tank, disassemble, clean, reassemble, and reattach to tank.

If needed, Z1E carries petcock rebuild kit.

Click > Rebuild Kit

There's an exploded view parts diagram on kawasaki.com included in the fuel tank diagram.

Good Fortune!

Is the filler cap check valved so only air in but not out?

gutter wrote:

Is the filler cap check valved so only air in but not out?

I don't think so (but not absolutely sure), otherwise you would get a pressurized gas tank parked on a hot day. Some cars may do that, but I've never noticed it on the bike.

gutter wrote:

Is the filler cap check valved so only air in but not out?

Thinking no check valve; just a circuitous channel designed within the cap to allow air movement both in and out which keeps pressure inside tank equalized with the outside atmospheric pressure.

Like holding finger over top end of a full drinking straw retains liquid inside straw until finger is released opening the top end to atmospheric pressure and fluid runs out of straw. Clear vent in fuel cap keeps finger away from the straw.

Without fuel tank venting from inside to out, undesirable pressure could build up inside the tank due to becoming heated from sitting in the sun.

Wasn't this as explained by Mr. Nye, The Science Guy? :laugh:

Good Fortune!

OK. The bike's running AWESOME!!

First thing, I just didn't plain have enough gas to bring it above the "ON" port. I filled the tank full and it worked fine.

Then I got a decent timing light and set my timing. And got a set of sync gauges.

Syncing did the trick!! I had one carb off by 2-3 (inches) ticks on the gauge. Adjusted and all was perfect. Wow this thing got some balls now. I got a front tire on the way and a new tach cable. My fiance just got her temps so it'll be her little bike. That's the only reason I got it all tuned up.

Had it just been for me, I probably would have half-assed it a little. haha. And I'll get some pics up soon.

One final step might be to invest in a good in-line fuel filter.Might save u grief down the line.bj

Well, I had bought a cheap paper one, but it was hard to fit under the gas tank and it didn't seem to allow the fuel to flow right. It had to loop around and flow uphill a little. I thought that was causing some issues. Then I see the one's on Z1's site. They look like a small copper air muffler on a pneumatic valve.

...running out of gas, it makes it quit every time.

The kz550 is an awesome bike. I wish I hadn't sold mine. My daughter wants to ride and that would be the perfect bike for her.