Internal gas tank vent

[nnwwfishman]

Hi,

​I have a Mercury 5hp 2 stroke with internal and external gas tank. I didn't use it for 2 years and forgot should I open the vent of the internal tank when I only use the internal tank. Thanks for help.

 

[roscoe]

yes, open the vent when using the internal tank.

If you don't, the engine will run for a little while, then there will be negative pressure in the tank, and fuel will not flow to the carb.

When using the external tank, open its vent when in use, well, unless it has an automatic venting cap.

 

[MH Hawker]

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