fuel shut off?

[paolo1]

i have aquestion my petcocks have three functions prime,on ,reserve. so how do you shut off the fuel flow from the tank if you need to remove it with fuel in there?each petcock has two outlets a vacum line and a fuel outlet

[mro]

Vacuum actuated,
on position is "off" unless engine is running

mro

[WMarshy]

If your petcocks are woking correctly then they shut off fuel when the engine stops making vaccum (is not running). Unfortunately, they have been known to leak when the engine is off and in return fill your airbox or worse, fill your engine oil full of gas. There is easy way to add an off position to your petcocks. Read more about petcocks by doing a search, there is enough reading material to keep you busy for a while.

[cywelchjr]

Just a reminder that if you get an airbox and/or crankcase full of gas when the bike is sitting that while you do indeed have a petcock failure that needs to be fixed, you ALSO have a carb needle valve failure that needs to be fixed just as urgently. You really DO need to fix both of them, as the needle valve failure can cause rich running and other problems even if the petcocks are working correctly. I've seen many bikes with manual petcocks that never turn them off, and don't have gas leaking. If the needle valves work correctly, they will NOT leak, ever. It's the primary reason for considering one of the needle valve upgrades on the earlier carbs, to get the viton tip, which does seal better than the metal to metal valves. If this was not true, they would not have switched to them in ALL the later bikes.

[motoman]

pull the fuel lines off the petcocks and if it still rips fuel, fix the petcocks CORRECTLY.......easy fix usually. Just clean inside of them after taking apart noting position of pieces and gaskets. Very lightly stretch the springs, use same gaskets, etc., light film of dialectic grease(same you use on the electrical plug-in) on the gasket pieces so things "squise" properly and I'll bet you won't see a problem for many years to come. That's all from personnell experience, if gaskets and diaphrams all look normal and not damaged.