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gt380 petrol tap...can leaky ones be serviced?
Posted: Fri Nov 08, 2013 9:41 am
by Ramjam
hi members
mine is leaking a but when the tap is switched on. I would say a bottom third of the tap head on, get wet with gas and drips. When the tap is switched in the off position, a little bit of gas leaks out of the outlet itself. can the whole thing be serviced? or is it time to order a new one?
thanks
mj in beirut
Re: gt380 petrol tap...can leaky ones be serviced?
Posted: Fri Nov 08, 2013 10:52 am
by pearljam724
Yes, at roughly $40 you can buy a rebuild kit. But, very rarely do the rebuild kits include the diaphragm and spring. Those 2 items often cause leaks on a petcock. Sometimes you can remedy the spring being weak by removing it and gently pulling on it about a quarter of an inch. When it comes to petcocks most of the time I opt to buy a new one. Saves a lot of headaches, as a rebuild kit doesn't always fix the problem.
Re: gt380 petrol tap...can leaky ones be serviced?
Posted: Fri Nov 08, 2013 1:01 pm
by ConnerVT
Aren't GT380 petcocks similar to T500 petcocks? As in, they have On, Reserve, and Prime? And no Off?
And yes, you can usually find the parts to rebuild them. Or, as many people do, install a new, manual one.
Re: gt380 petrol tap...can leaky ones be serviced?
Posted: Sat Nov 09, 2013 5:39 am
by Ramjam
how does one go about servicing them? How easily do they come apart? where to start?
MJ
Re: gt380 petrol tap...can leaky ones be serviced?
Posted: Sat Nov 09, 2013 7:02 am
by Ramjam
i just opened it all up as i concluded that my question about servicing was pretty silly. On the circular tap side, i noticed that the previous owner appeared to have bent the washer inside the bowel, presumably to put more pressure against the cyclinder to stem the leak of gas (?).
WOuld i be right in saying that the thin rubber seal around the edge is what is worn and needs changing?
thanks
mj
Re: gt380 petrol tap...can leaky ones be serviced?
Posted: Sat Nov 09, 2013 8:53 am
by Coyote
That washer is not bent. If you buy a new one, it will look exactly the same. I's made that wa7 to hold tension against the rubber 4 hole gasket. The 4 hole gasket is a good place to start in trying to fix it. Sometimes you can get by by simply flipping that gasket over, before running out and buying a new one. There is no off position on these petcocks Just run, reserve and prime. The spring loaded diaphragm duold shut te fuel off when the motor is not running in both the run and reserve positions. Prrime is for filling dry carbs.
Re: gt380 petrol tap...can leaky ones be serviced?
Posted: Sat Nov 09, 2013 9:04 am
by pearljam724
Re: gt380 petrol tap...can leaky ones be serviced?
Posted: Sat Nov 09, 2013 9:34 am
by Ramjam
but the bent ring should go between the plastic four-whole plastic 'filter' and the end of the tap? Or does it go inbetween the outer metal surround and the front of the tap? (this is what i did to tension it and improve it)
Re: gt380 petrol tap...can leaky ones be serviced?
Posted: Sat Nov 09, 2013 11:04 am
by oldjapanesebikes
Ramjam wrote:but the bent ring should go between the plastic four-whole plastic 'filter' and the end of the tap? Or does it go inbetween the outer metal surround and the front of the tap? (this is what i did to tension it and improve it)
Martin - if you take a moment and look at a parts listing, the order of assembly is shown eh ?

In the package I sent to you, there are a couple of extra bits and pieces which should help. Should be there by the end of next week or the week after.

Re: gt380 petrol tap...can leaky ones be serviced?
Posted: Sun Nov 10, 2013 9:05 pm
by Coyote
Or does it go inbetween the outer metal surround and the front of the tap?
yes