clearing tank vent

[Kevin Hollis]

Hi,

I'm starting off with the simplest problem for my bogging down under 
hard acceleration. (Also, the filler cap whistles for a couple of 
minutes after I stop, so I'm guessing an obstructed fuel tank air vent.)

I have no air line so how do I clear the air vent ?
Just poke a wire/pipe cleaner down it ?
I want o check there isn't some clever diaphragm that I'm going to break.
Where does the hole go to? Just a couple of centimetres directly into 
the tank?

thanks
Kevin