Hi all - quick question for anyone familiar with GT250M's ..
The vacuum petcock fuel tap (the one which uses two bolts to fit to tank, like in the attached image) - does anyone know of an aftermarket non-vacuum petcock alternative available to fit this model?
I've had it with the crap OEM vacuum ones - they all leak like sieves.
Thanks
GT250M fuel tap petcock
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GT250M fuel tap petcock
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- Alan H
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Re: GT250M fuel tap petcock
Buy genuine then.
Who are you anyway? A nice intro is appreciated before the 'I want/need' stuff.
Who are you anyway? A nice intro is appreciated before the 'I want/need' stuff.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
- jabcb
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Re: GT250M fuel tap petcock
You may have the same type of problem I had with my gray GT750.
Petcock was leaking. Replaced it with a new petcock which worked fine for a short period of time & then also leaked.
When I removed the leaking petcocks, the inlet filters (the filters that you can see in the pic) had come off & were in the tank.
I took the second petcock apart & found some small bits of crud interfering with the diaphragm o-ring. As a result the vacuum mechanism couldn’t close completely & the petcock leaked.
The little screen filter at the bottom of the petcock is after the diaphragm. Without the inlet filters, the diaphragm mechanism is exposed to unfiltered fuel. Not a problem with a clean tank, but the leak was inevitable given the condition of that GT750 tank.
A while ago I asked about this problem on this forum & the GS forum. A smidgen of JB Weld will make sure that the inlet filters stay put. Don’t use too much because it has to fit the tank opening.
Petcock was leaking. Replaced it with a new petcock which worked fine for a short period of time & then also leaked.
When I removed the leaking petcocks, the inlet filters (the filters that you can see in the pic) had come off & were in the tank.
I took the second petcock apart & found some small bits of crud interfering with the diaphragm o-ring. As a result the vacuum mechanism couldn’t close completely & the petcock leaked.
The little screen filter at the bottom of the petcock is after the diaphragm. Without the inlet filters, the diaphragm mechanism is exposed to unfiltered fuel. Not a problem with a clean tank, but the leak was inevitable given the condition of that GT750 tank.
A while ago I asked about this problem on this forum & the GS forum. A smidgen of JB Weld will make sure that the inlet filters stay put. Don’t use too much because it has to fit the tank opening.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more
Suzuki:
GT750 2x75
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Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
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Re: GT250M fuel tap petcock
jabcd - thanks for the helpful response. I've had problems with the GT vacuum petcocks for what seems like forever (!), so anything that might remedy the issue of leaking petcocks is most appreciated. The one on the bike is a 'genuine NOS' item, which leaked within a day of installation. It will shortly have to join the spare ones on the bench, and I'll be doing yet another attempted overhaul to try and fix the leak. Note your comment about using the JBweld - thanks.
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- Yeah Man, the Interstate
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Re: GT250M fuel tap petcock
You can modify the vacuum petcock to be a manual on off reserve, I have done most of mine, and all you need is a couple of set screws and epoxy.
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71 T250 scrambler
75 T500 cafe
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Re: GT250M fuel tap petcock
karl pa - that sounds like a good option; are you able to explain your process further, and did it cure the slow seepage issues that the vacuum diaphragm system often causes when its not working 100% ?
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- Yeah Man, the Interstate
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Re: GT250M fuel tap petcock
On the newer style petcock with 5 ports.
I remove the diaphragm and tap the inlet port, insert set screw with epoxy, remove fuel bowl and tap port from diaphragm to bowl port, insert set screw and epoxy. remove handle valve and remove the material between passages to make one reverse J passage.
If you look at the ports of the petcock, the port at 12 is main tank supply, port at 3 is reserve supply, port at 6 is fuel discharge to bowl, port at 9 is blank, port in center is to diaphragm that is plugged by set screw.
when handle is turned front, passage connects port 12 [main] port 9 [blank] port center [plugged] and port 3 [reserve], off position fuel can't flow
when handle is down, connects port 12 [main] port center [plugged] port 6 [bowl] and port 9 [blank], on position.
when handle is back, connects port 9 [blank] port center [plugged] port 3 [reserve] and port 6 [bowl], reserve position.
On the older style with 4 ports.
I plug the inlet to diaphragm and outlet from diaphragm to bowl. I then reinstall handle 180 degree reversed. Handle pointer up is off position, but I am not sure anymore where on position is and where reserve position is.
I no longer have fuel seepage issues, only problem is to remember to turn on and off, but with most converted it is easier to remember.
I remove the diaphragm and tap the inlet port, insert set screw with epoxy, remove fuel bowl and tap port from diaphragm to bowl port, insert set screw and epoxy. remove handle valve and remove the material between passages to make one reverse J passage.
If you look at the ports of the petcock, the port at 12 is main tank supply, port at 3 is reserve supply, port at 6 is fuel discharge to bowl, port at 9 is blank, port in center is to diaphragm that is plugged by set screw.
when handle is turned front, passage connects port 12 [main] port 9 [blank] port center [plugged] and port 3 [reserve], off position fuel can't flow
when handle is down, connects port 12 [main] port center [plugged] port 6 [bowl] and port 9 [blank], on position.
when handle is back, connects port 9 [blank] port center [plugged] port 3 [reserve] and port 6 [bowl], reserve position.
On the older style with 4 ports.
I plug the inlet to diaphragm and outlet from diaphragm to bowl. I then reinstall handle 180 degree reversed. Handle pointer up is off position, but I am not sure anymore where on position is and where reserve position is.
I no longer have fuel seepage issues, only problem is to remember to turn on and off, but with most converted it is easier to remember.
76 GT185
77 GT250
77 GT380
76 GT500
73 GT550
73 GT750
74 GT750
71 T250 scrambler
75 T500 cafe
77 GT250
77 GT380
76 GT500
73 GT550
73 GT750
74 GT750
71 T250 scrambler
75 T500 cafe
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Re: GT250M fuel tap petcock
karl pa - That looks like a proper solution to a perennial problem - thank you very much for sharing ! I'll be giving it a go with one of the leaking taps this weekend.