Kz900 Rectangular bolt mounted petcock

Got a kz900 1976 and it suffers with stuttering occasionally almost like fuel starvation. It had been left for a while by previous owner and so I cleaned the carbs set float heights and balanced them the used fresh fuel. It still plays up and so I wanted to fit a new fuel tap and give the tank a swill round to get any debris out. My question is that all the fuel taps I see are the round style that fit onto a threaded spigot on the tank. Mine has a rectangular base that bolts onto the tank and only has one outlet. The pressing on the bottom of the tank has this same shape so it appears to be correct but I cant find any info nor have I seen one similar. Im also concerned that its single outlet goes to a tee piece then off to each supply on right hand and left hand carb inlets. Anyone recognuse this?

Your petcock looks the same as the one on my 1977 KZ650 (see images below). The parts diagrams show the round style petcock on all the KZ900 models. Maybe someone installed a fuel tank on your bike from a different model KZ. Ed

That tank must be from a different bike. Unless you have big carbs and big bore kit, you shouldn't be running out of fuel. Did you check the sediment bowl? It has a screen in it that could be clogged by debris. Check the vent in the gas cap as well.
Steve

Thanks for the reply 650ed. I was wondering if it was a different tank or if they changed them late in the production run. Ive checked kz1000 and they seem to be the round sort too. Your petcock certainly looks the same. Do you know if the 650 tank was the same shape as the 900? Has yours got a single outlet with a tee piece in the lines?

Swest, Tried to get the sediment cup off but wouldnt shift and worried about shearing it and having no petcock at all. Will havev to try the usual persuasion techniques.

It seats against a rubber gasket. I use a thick O ring in it's place. You might try heating it with a heat gun or hair dryer then turn the bowl. The threads are very fine so be careful not to mung them up.
Steve

zak900 wrote: Thanks for the reply 650ed. I was wondering if it was a different tank or if they changed them late in the production run. Ive checked kz1000 and they seem to be the round sort too. Your petcock certainly looks the same. Do you know if the 650 tank was the same shape as the 900? Has yours got a single outlet with a tee piece in the lines?.......

My petcock has a single outlet and my carbs are fed by a single fuel line, so I don't have a tee.
I think the tank shapes are a little different. The images below show the dimensions of the mounts on the bottom of my tank. Mine has a tang at the rear (see orange tank pic below) that engages a rubber piece on the frame and two semi-circular mounts near the front of the tank that engage two rubber pieces near the front of the frame. The distance from the center of the tang to the center of the front rubber pieces is about 18 inches, and the width of the tank at the rubber pieces is about 4.5 inches. Ed

650ed wrote:

zak900 wrote: Thanks for the reply 650ed. I was wondering if it was a different tank or if they changed them late in the production run. Ive checked kz1000 and they seem to be the round sort too. Your petcock certainly looks the same. Do you know if the 650 tank was the same shape as the 900? Has yours got a single outlet with a tee piece in the lines?.......

My petcock has a single outlet and my carbs are fed by a single fuel line, so I don't have a tee.
I think the tank shapes are a little different. The images below show the dimensions of the mounts on the bottom of my tank. Mine has a tang at the rear (see orange tank pic below) that engages a rubber piece on the frame and two semi-circular mounts near the front of the tank that engage two rubber pieces near the front of the frame. The distance from the center of the tang to the center of the front rubber pieces is about 18 inches, and the width of the tank at the rubber pieces is about 4.5 inches. Ed

Great info and pics, thanks