Intake manifold hose

[AnglersEdgeNY]

A quick question regarding the nipple of the bottom of the intake. All the nipples are clear, meaning I can blow air through them except for the one shown in the pic. Before I go any further should this passage be clear like the other ones?
Johnson 225 1986

 

[ezeke]

Re: Intake manifold hose

I believe that you are pointing to the fitting for the air silencer drain, which should be open to allow excess fuel to be pulled into the engine from the air silencer base.

The other fittings should be recirculation check valves which only allow flow in one direction.