May be a bit complicated for this forum but,.. Is it o.k.to increase the diameter of the right hand side small diam pipe that comes from the banjo and connects to a stepped hose and joins to the crossover pipe filler? I ask this as its always this small tube that clogs when laid up for the winter. Or is this also a venturi?

 

No reason I can see or think of.

There was a one valve report to be in that section near the fill spout, I have never seen that valve in any of mine.

The banjo cross drilling error, especially with "standard" copper washers, is the main cause of restricted flow that I have found.

We dont store for Winter, or any other season, so I have NO experience with what happens there.

 

Quite OK, nothing to do with the venturi. Great idea too.