World Formula Exhaust Silencer - USA Spec 0039 due to the recessed needle

due to the recessed needle bearing area per the design

Overall Dimensions: 22mm OD shoulder (where it fits into spindle-yolk)

Check out the Swift LV wheels

Each starter also comes with an o-ring that fits into the bendix unit for a tight seal

World Formula Exhaust Silencer - USA Spec 0039 due to the recessed needleExhaust Silencer for the World Formula Engine, USA Spec. This silencer is the perfect accessory for your World Formula engine if you are racing it in the United States! Overview Manufactured by RLV USA for Briggs & Stratton, EXF4108 is a precision manufactured exhaust silencer for the World Formula engine. This exhaust silencer fits over P N 5950, the World Formula exhaust pipe to keep the engine operating properly, encourage smooth exhaust flow, and