(7.) Opening the throttle raises the slide, exposing the needle. Here's a front view of th
Air/fuel Adjustments
There are no jets to change or accelerator pump to fiddle with when making air/fuel ratio adjustments on the Genesis Big-Air carb-all adjustments are made externally in seconds. The carb includes three simple fuel circuits: pilot fuel (low speed), needle (midrange), and powerjet system (main). It also has a pilot air circuit. Since all circuits are externally adjustable, no disassembly or carb removal is required for tuning. All midrange tuning of the needle, the foremost tuning circuit, is accomplished by turning an external 25-clicker adjustment screw located on top of the carb. The clicker moves the tapered needle up (richer) or down (leaner) the equivalent of 15 jet sizes. Three different slide designs are available based on engine displacement: mild, medium and aggressive. PSI conducted extensive testing of slide and needle combinations, so the combinations are highly developed for great throttle response for various engine combinations. The flat slide design, ribbed walls, and vortex generators produce highly atomized and vaporized fuel, eliminating the need for a conventional accelerator pump to prevent low-speed stumbles. For cold weather starting, a push-pull enrichener is located near the top left of the carb for easy access.
(8.) Shown is a backside (manifold side) view of the carb's venturi with the slide open. N
The Genesis Big-Air carb is a direct bolt-on to an S&S Super G two-bolt intake manifold and utilizes the Super G's three-bolt pattern on the air cleaner side. It also has the same width front to back (3.515-inch) as the Super G Shorty carb. For throttle control, the carb is available with either a single cable pull for a clean, simple design or optional second cable on the newest model, the Series 4. The new Genesis Series 4 carb includes several enhancements over the earlier Series 3, including a larger float bowl, shorter throttle pull, and enhanced vortex generators, just to name a few. PSI's carburetors come with a three-year warranty and are available in bright dipped clear anodized billet, bright black anodized or chrome plated finishes. Also included with every carb are installation and tuning instructions along with a setup sheet showing all fuel circuit settings and the exact slide and needle installed at the factory.
(9.) After removing the float bowl and top cover, the two-part carb body is disassembled b
Conclusion
PSI may be new to the V-Twin performance industry, but after a first look at the Genesis Big-Air carb, it becomes clear that PSI is bringing some fresh ideas to a matured industry. The Genesis carb is a highly sophisticated design with V-shaped technology, yet simply engineered with three external fuel adjustments and one air adjustment for easy tuning. When those benefits are combined with impressive looks, quality components, and the ability to meet 2010 emissions standards, you have a winning combination. Moreover, PSI says the Genesis Big-Air carb is so simple, even a caveman can use it.