Keihin 42mm 42 mm PWK Carburetor Carb Honda CR500R CR500 CR 500R kx500 Lt500 January 10, 2024 admin New old stock, unit was bored from 39mm to 42mm and a CNC machined velocity section for slightly more top end performance. Categories: keihin Post Tags: 42mm 500r carb carburetor cr500 cr500r honda keihin kx500 lt500