The BIG97 Secondary carburetor is designed ONLY to be used in multiple carburetor systems, connected to a BIG97 Primary with a progressive linkage. BIG97 Secondaries have no power valve or accelerator pump circuits, but keep chokes, idle and transition circuits for steady idle and good low throttle manners. Dummy accelerator pumps retain the classic 97 look.

55% more airflow
BIG97s move up to a 1.175in venturi with super-efficient 20 degree entry angles. And flared exit cones build power by slowing the mixture down to reduce turbulence into the manifold plenum. The result? 250cfm per carburetor.

New 'early plenum effect' boosts top end power
Allowing all cylinders to draw from both barrels gives you dual-plane drivability with a single-plane style top end horsepower.

BIG S-jet twin-ball inlet valve
Accepts big diameter 5/16in hard line (regular 97s take only 1/4in line), plus regular Stromberg fuel fittings.

All Genuine 97!
Everything that makes the Genuine Stromberg 97 so popular is built into the all-new BIG97. From the cast iron base to the reinforced air horn casting and everything in between.

Runs out of the box
BIG97s come ready to run with the following jetting (see below). As with any carburetor, rejetting may be required for other applications, high altitude, local gas, ethanol content and more. A wide range of jets and power valves is available.

BIG97 Secondary jetting:
Main jets 0.061in No Power valve. No Accelerator pump valve

• All Genuine 97 on the outside
• Totally new on the inside
• BIG 250cfm airflow - 55% more than a regular 97
• New ‘early plenum effect’ boosts top end power
• BIG S-jets accept 5/16in hard line
• Runs out of the box.
• Use ONLY in multiple carb systems, connected to a Primary with a progressive linkage

Product Reviews for STROM9510A-BIG-S - STROMBERG