Re: OMC remote gas can cap question

[frankr]

Those pins have a tapered head on the inner end. That tapered head seats in an o-ring. If the o-ring has some sort of deformity, it can affect how far the spring pushes the pin outward.

As said the vent is one-way. It admits air as fuel is consumed, but does not let air out (or let fuel slop out). So pressure increase in the sun is normal. Your carburetor float valve is supposed to be able to hold against that pressure. Of course you can use the Redneck cure and loosen the cap.