Re: silencer drain?
I assume it is the same thing as on my 1975 135HP. It drains the fuel that just so happens to collect in the bottom of the silencer and drains it down into the engine where it will be burned at some point.
I do not have a gasket on my cover and thus the fuel just leaks out the bottom of the silencer. I plan on putting a gasket back on to stop this but have other issues to worry about right now. There is always some fuel puddled under my carbs because of this (albeit mostly the 2-stroke oil since the gas evaps). So if you do not want the puddle under the carbs, I'd leave the hose intact.