fuel tank

I have two tanks for this ride one is stock with rust and holes in it 3gl i was told . the outher is in good shape 5gl?the problem that i have is that the fuel shut off valve area is square? not round like all the service manuals say .what kind of tank is it??? can i still use this tank for a kz900? and what kind of fuel shut off valve do i use??
thank you for your reply.

Are these tanks that were on your bike? Are these spare tanks you picked up? Pictures would be an enormous help:)

Here are the pics of the tank in question.

I think that is a tank from a '78 KZ1000-A2A. Its capacity is closer to 4.5gal.

You will need to get a bolt-on petcock (as opposed to the screw-on round one). If you can't find a KZ one, you can get a new Suzuki petcock from Z1E for cheap that works perfectly (I have one on mine with that same tank). Here is the link to the petcock:

www.z1enterprises.com/detail.aspx?ID=1716

That tank "should" fit on your 900 frame.

If I interpret your questions correctly, the photos are of the tank you want an ID on. I am also assuming that the picture of the underside of the red tank is also the underside of the blue tank. If so, the tank is from a 1978 KZ1000A2 model. You'll have to locate a petcock from the same bike and it will fit on a 1976/77 KZ900A4/5 frame.

the under side of the tank is red and the rest is blue,will this still fit on my 1976 kz900b?.the outher tank that came with the bike is smaller,and has alot of rust in it.and puddy on the under side i'am not going to use that one.
thanks for the reply

Yep, tank should also fit on the KZ900B frame:)

Don't mess around. Drop a C note on a pingle.
They's made in the USA.

www.pingelonline.com/

KZCSI