When Andrew started making them, the 1st generation carbs were made with a Holley Carb needle valve (screw in type) and didn't work very well as the needles were very long, made of steel and too heavy to be used in a pumper carb, then after many complaints (from me as well/my team was sponsored with Buckshot carbs) he updated them to the STD. Mikuni push in needle valves.
These were a lot better to tune. worked good for race ski motors, just not sure if they would work for a freestyle/freeride setup to stay clean off the bottom throttle response.
Most of the old jetting notes I have is for HX 720's and XP800's.
These also were spigot mounted on the seadoos, now I know not to do that on yamaha engines (need to be solid mounted) so I haven't ever tried them again.
