1975 GT750 Petcock Leaking through

[Vintageman]

Hello,


When my 1975 GT750 sets for a time, I know the Petcock is not blocking fuel as it supposed to, allowing fuel to pass to carbs. I think I can see that an O'ring is missing in the Petcock diagram shaft and possibly why it leaks through. Does anyone know of a replacement O' ring that fits or rebuild kit for petcock in general?

I am OK converting it to manual petcock if can't repair it. I saw a post on this topic where Jabcb had replied with a link to a post of his showing what he did for example to make it manual, but that link went no where today.

If I can repair leaking petcock with Oring that is preferred, Or converting to manual is OK too, but I want a definite OFF position so I know it not leaking during storage.

Thanks

[jabcb]

A shop in Germany sells repair kits:
https://hard-to-find-parts.de

There are some inexpensive replacement petcocks on eBay. Don't know how good they are.

[Vintageman]

Thanks I have tried a couple aftermarket one and even the one I have now, which cost a bit more than others with Vacuum one off seems to leak through.

The .de link showed me a pic of diaphragm and indeed my o-ring has disappeared. This sized hinted and what the size of the oring may be O-RING:4.0 X 2.0MM ->
https://dealer.klsupply.com//carb-fuel/ ... ir-kit.asp

I bought some from Grainger and will reply how it works out. I think I have couple petcocks and will see if same oring.

Thanks again

[karl pa]

The 74 and newer petcocks are different than the old style petcock and needs modified in a different way.