TOPIC:

Bike runs great at present with the tap in the "prime" position, took it for a run for an hour or so at high revs, seems to supply fuel well, no lack of power, so no lack of fuel, just have to get the vacuum hose sorted, thinking of some 90 deg elbow onto the vacuum line at the tap to try and run the line away from the tappet cover, if not, some reinforced vacuum line, i'll check out a few stores on the weekend, cheers

Try the same run without much fuel in the tank. The 10" of fuel will give you a bit more pressure when it's full, that way you'll know if it is good right to the last.

No eBay APP ID and/or Cert ID defined in Kunena configurationFor those that might be interested in getting better flow than the gpz taps but retaining a vacuum shutoff valve, there's an after-market in-line valve that can be bought as well. Looking around this morning on Ebay most valves of this type are made for scooters but the Pingel one I found below looks to allow adequate flow for our bikes. So another option would be to keep/rebuild the original tap, fit this in-line shutoff, somewhere between your filter (if you have one) and your carb and you should have the same effect with improved flow. Combine this with a Pingel tap and I see no reason why a bike would have starvation issues!




Kind of funny the myriad of things we fit to our bikes for fuel flow/regulation just as an in-line option. Filters, strainers, shutoff valves (electronic or vacuum), electric pumps, vacuum pulse pumps, carburetor line pressure regulators etc.

I've been considering experimenting on my own with a pump setup: gpz petcock, in-line filter (or two), pump, t connector with return line, holley style pressure regulator then finally carbs. Not completely sold yet as the holley is only adjustable from 1-4 psi and I would like to find something that goes under 1psi in case 1psi is too much pressure .

Hi guys

had to remove the tank to fit the cable for my navigation so I thought I take some pics to show how looks like with my bike.

I need to admit that after fitting the tank back again the performance was not as used, I used to ride for approx. 40kms with the petcock in prime-position to flood the circuit. After a while the perforance improved and the bike ran smoother, especially whan accelarating. I guess a lot of problem result from the way you lead the hose around.

What you do not see on the fotos is the manual valve I have installed, basically similar to the one Mikez showed on Ebay.

Here the pics:

Guess you can the tha vacuum hose and the Y-connector to split it on two carbs as well as the fuel-hose that runs from the petcock to the other side (left) of the bike and back again, going throug the filter and finally down to the carbs.

Hope it helps:

regardz

Holger

Asked Helmut at MCG in Germany the best way to connect the vacuum line, he was nice enough to answer my dumb question, as he sells the taps and fits them I guess he'd know, here is his answer :-

Hello Pete,

you can use it with vacuum, connect it with the first or second cylinder inlet (there where the screw is) make the tube so short as possible.

you also can use it without vacuum, then the fuel tap is open on PRI and closed on ON + RES, please notice then you have no reserve.

The best function is if you use the fuel tap without vacuum

Best Regards
Helmut - MCG

I have one of these and I opened up the back of the fuel tap and rotated the vacuum pickup to 180 degrees from original position, problem solved