Need Petcock Help

[bones]

just bougth 83 gs550 ld petcock has prim/on/resv how do you shut gas off

[txironhead]

The petcock is vacuum operated and should turn off automatically if it's working properly. Some models have a designated off position, doesn't look like yours is one of them. PRI is prime and the fuel will run whether the bike is running or not, the other two positions should not allow fuel to flow with the bike off.

[Billy Ricks]

just bougth 83 gs550 ld petcock has prim/on/resv how do you shut gas off

As long as the petcock is functioning properly it turns itself off when the engine is killed. It works off of vacuum. As long as the diaphram doesn't leak in the petcock when there is no vacuum fuel flow stops.

[gustovh]

carefully remove the back of the valve, there is a spring in there. Carefully remove the diaphragm and replace the O ring, 6mm I believe. Clean the seat, replace the diaphragm, spring and back. The valve should not run gas. Suck on the vacuum hose to the valve and gas should flow. Place on prime and gas should flow, place on reserve no gas, suck on tube should get gas.
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