TOPIC:

I've got a Honda that has a Vacuum fuel shut off. There are four nipples on the unit: fuel in, fuel out (can't mix those up -doesn't matter anyway) and Vacuum in, and a vent port that allows the fuel diaphragm to move when Vacuum is applied to the opposite side. Both the Vacuum In and Vent port have the same size nipples and hoses attached. Not really easy to mix them up because of the way they're mounted on the Honda carbs but if they were hooked up backwards, no fuel would flow. Is it possible this is the case with the tap you have?

Hi Bucko,
Thanks for your reply.
The GPZ900R petrol tap relies on a vacuum pipe from the manifold to SUCK and pull the diapram back against the inner spring to let the fuel flow.
Its a very simple process.
Its impossible to get it wrong ..............unless there is a problem with the tap, which I am beginning to think maybe the issue.

Pete F
UK

Biltonjim,

Thanks for your reply..........................and believe me, I am 100% fully aware of one of all my posts on this issue (and every other post) including the one 6 years ago when I had similar problems, but have fitted the same tap since on others without issue (as mentioned earlier).
The tap can and will work with one vacuum feed pipe from one outlet on any of the 6 cylinders on a Z1300, as other owners have confirmed and I have been successful with on many occasions.
As mentioned earlier, the tap has the ability and capacity to feed all 3 float bowls in the PRI position which proves it is a worthy solution.................but on the particular tap I have............for some reason............it wont feed enough fuel when relying on vacuum suck at higer revs, which is not an engine issue, its a tap issue.

My initial question and query was to anyone who actually HAS one of these taps fitted to their bike (rather than just opinions) as politely mentioned in my first post on the matter, to prevent replies I dont need.
I dont have time to start any carry on with vacuum pumps and what have you, as its not necessary.......................I was looking for someone who may have had the same issue if they have fitted the same tap to a 1300 and found a proven solution to it.................hence the paragraph in my first post.

Thanks anyway

Pete F

Mizz,

Thanks for the reply and your photos (appreciated), which are very interesting indeed.

I "guess" your petrol pipe comes out of the tap as shown, then wraps around the outside of the frame tube then back to the top of the carbs and into the inlet feed nozzle ?
I have never seen this done before on any 1300, but its obviously a viable solution if it works for you on your 1300 and allows enough fuel out to feed the 3 float bowls at prolonged high revs in the ON position.
This was just the type of reply I was hoping for ,,,,,,,,,,,,,,,all be it not a solution for the GPZ900R tap issues, but a good one anyway!!

I would also expect this solution will make removing the pipe from the tap far easier when removing the tank, as the standard tap nozzle is a complete Ba$tard to get to !!

Great food for thought and a proven solution.

Pete F
UK

Hi Pete,

You’ve described it perfectly. The original tap was beyond repair and the task was to find an alternative at a reasonable cost. A Suzuki GT750 will also fit but at over £120 for a new one it was a bit expensive. This turned out to be the best alternative. I originally thought that the seat would crush the hose when sat on the the bike but that’s not the case. I’ve also not had any problems at high speed. 70 mph of course.

Mizz,
Thanks for your reply.

In my opinion this is what an owners club site is all about...............practical and cost effective solutions to upgrades, modifications and fixes for our 1300, to make it possible to keep them going for the years ahead.
Opinions and speculations are always there, but proven tried and tested solutions are what we need and priceless !

Thanks for sharing your solution here, which I assume many will benefit from.

Regards

Pete F
UK