Square carburetor from the Mikuni Pro Racing Super BN46 Series, BN46-42-8002.

Mikuni High Performance Super BN carburetors are engineered for high horsepower racing watercraft. The Super BN Seriws offers enhanced airflow, higher capacity fuel pump, externally adjustable metering screws, and replaceable jets for straightforward high and low-speed tuning. Extensive testing has optimized air and fuel flow to deliver maximum performance.