82 GPZ750 tank breather

[Eastoe]

still having trouble with a leaking fuel tap after fitting a new diaghram.
I want to check the fuel tank breather but I can't find it. Is it in the cap? any suggestions?

[h.b.bear]

The air breather is in the fuel cap, but with the fuel leak maybe it was put together wrong to start with and you have replaced the new kit the same ?

[Eastoe]

I'm comfortable with the way the tap went back together.
Where in the fuel cap is it? I want to check that it is clear. I'm expecting it probably is.
do these mikuni carbs only have one vacuum line coming off them?
There are 4 vacuums on the carbs and only 2 are capped on mine. not sure if I've lost a cap off the 3rd one or if it could have another vacuum line going to the tank as the fuel guage has a vacuum connection.
I've crimped a hose over it for now and replaced the tap with a GSX Suzuki tap. (bolts straight up but the hose connections are at a different angle)

[h.b.bear]

Had a look at mine tonight and it has one pipe coming from the second carby from your left sitting on bike and the other pipe which is your fuel feed as mine has a inline filter on it, it goes to the centre of the 4 carbys somewhere, the others on the carby are all caped off.

[Eastoe]

thanks for cheking. looking at a complete bike is a good way to clarify.
I've stuck with the GSX fuel tap and all seems fine now.
Rode it over for a rego inspection late yesterday so it should have a plate on it today.

[Gosling1]

.....still having trouble with a leaking fuel tap after fitting a new diaghram.
I want to check the fuel tank breather but I can't find it. Is it in the cap? any suggestions?......

the leak could be coming from where the tap actually bolts into the tank ? I had some problems with this on my 650, it uses pretty much the same tap. You need a new O-ring (its actually a long oval-shaped O-ring) and some new fibre gaskets which sit under the body of the tap, one for each mounting bolt. A leak in this area will just run down the external body of the tap and looks like it could come from the diaphragm area......

the tank breather is just a small hole - you can see it on the underside of the tank cap, in the centre section inside the rubber gasket. It breathes through a small circular passage which you can see if you pull the cap apart. This passage ends up still on the underside of the cap, but outside the gasket area and above the gasket-sealing surface - allowing the tank pressure to equalise as the fuel level drops.

A quick blast with the air-duster in the small hole you can see, is always enough to clear the breather in these caps.

You should have 3 of the vaccum take-off points blanked off with small rubber caps, and 1 take-off point ( the one located between #1 and #2 cylinders) - is the vaccum take-off point for the fuel-tap fitting. This hose is the smaller diameter hose.

Will be good to see some new pics of this rig mate

[Eastoe]

All rego'd now and running fine.