your kayak the valve "stem" should be set into the "down" or "inward" position.
the stem should be in the up/outward position.
In the (Inflate) up/outward position air can be pumped in bypassing the spring-loaded plunger, but it cannot escape. (Note: If the top of the stem is almost flush with the rim of the threaded valve then it is in up/outward position, known as the inflate position.) If your valve is in the Inflate position and you want to set it to the deflate position, this is done by pushing the stem down/ inward with your index finger, then rotating your finger 1/4 turn. This step is repeated to move back to the Inflate position. When you release your finger the stem should remain in the down/inward position. The deflate position allows air to flow in or out unrestricted. If you are using a 12v inflator to inflate your kayak you may need to have the stem in the down/inward position as the 12v pump most likely will not have enough pressure to bypass the spring loaded plunger when the valve is in the up/outward (inflate) setting.
Using the NEW "Screw-on" valve adaptor:
The screw-on valve adaptor was designed to enable the pump hose to securely connect to the valve without falling off during inflation, making inflation easier. The valve adaptor also has a semi-circle protrusion that will depress the stem and open the valve slightly to allow pumps with pressure gauges to take a constant reading. When inflating the kayak using the Screw-on valve adaptor, the valve should be in the Inflate position.