Sean and Chuck,
correct me if I'm wrong but isn't the Aqub 42x55 prop a bit big for the .18?

The reason I ask is according to the chart on Aqub the 42x55 is equivalent to a Prather 230 and a 230 is what we use with the K&B 7.5cc (.45) on the Tunnels.

and I tend to agree with chuck also, it sounds lean. let us know how many turns out you have on the HSN.

Dan.