Help me identify this petcock

[Guest]

Hi
so i got a GS450 Tank from Ebay
The petcock is little difference the the one i got in the GSX 400 tank
This is it





it got only ON and RES no PRI or OFF.
what's the little brass screw on the front?
The GSX 400 one looks a little diffrent and has PRI, but it seems to be in a worse condition then this one.
what rebuils kit do i need for this one?

Thanks
Eran

[Tamara]

The little brass screw is Prime. I have a 450 and the petcock on mine doesn't look like that one.

[tom203]

While folks are looking, maybe someone knows where this one came from- the guy I bought it of had no clue

[pete]

Eran, that's the stock 80 - 82 450E/S fuel tap/petcock.

Tamara's right that the brass screw is for prime, just loosen it off for 30 seconds to prime then tighten again for normal running.

The small nozzle is the vacuum port and the large nozzle is fuel outlet, however it should face directly backwards rather than towards the front like it is in that photo.

Here's my brand new one for comparison:



And installed... sorry you can't really see the fuel outlet but that's because it is facing directly backwards as it should:

[eran_k]

Thanks Pete, Do you know which rebuild kit is needed for it?

[pete]

Can't help you there I'm afraid, when mine failed I bought a new one.

The issue with these particular ones appears to be the metal disc inside that shatters and stops the tap turning. That's what happened with mine and I've seen several others on here report the same issue.

Unfortunately none of the rebuild kits include that metal disc so a rebuild kit is useless if that's what's wrong.

[eran_k]

Well, it's turning and seems to be in good condition, is there a way to test if off the bike?

[pete]

Only way I could think of is sit it so the fuel nozzle is facing up, put a little fuel in, and see if it runs out through the fuel filter.

If it doesn't, then apply some vacuum to the vacuum port and see if it runs then.

If it runs without vacuum, then it's leaking.

If it runs only with vacuum, then that's a good sign.

You could probably safely substitute fuel with kerosene or water or something too.