Precision Matters: Zenith NDIX
To make 'street horsepower'.

The claim is as follows: 32mm carbs are too small for a 1720cc four-cylinder street engine. 40mm carbs are too big for a 1720cc four cylinder street engine36mm carbs are just right...
The Zenith 32NDIX carbs work best among the factory carbs in our test speed range. But they were maxed-out at the 32mm butterfly diameter by the time of the B Super. Not good enough; the factory wanted performance at 4-5,500 RPM, so they fitted a very large venturii for this size throttle bore. This mix meant a weak 'signal' as the air mass passes the venturii, so proportionately very large jets were fitted to compensate. All band-aid solutions, but ones which work surprisingly well. But 36mm carbs satisfy the formulas for this size four-cylinder engine in the 5,000 RPM range and the throttle/venturii diameter ratio is right on the money. Jetting should therefore be more predictable and perhaps more economical. There exists a Zenith 36NDIX carb built for a very small market, but which bolts right on to the stock Zenith manifold. We're sourcing these from various suppliers and have designed and developed the required modification to the stock manifolds. All in all, it has turned out to be a very effective solution, with the carbs and manifolds resulting in a direct increase of over 10% horsepower at engine speeds under 5,000 RPM with no other modifications at all.

Call for pricing and information: +44 (0) 1787 476338