RE: ASP FS61 midrange problems
Some people run the Enya A3 in their four strokes. it is a hot series plug and is the one that comes in the Enya four strokes
You are correct, the flat area of tuning for the HSN is getting into the danger area. You are supposed to be on the rich side of this flat spot.
The Sag when vertical is a indication that you are too lean